   Link: alternate
   Link: license
   Link: canonical

                              Conversion of units

   From Wikipedia, the free encyclopedia
   Jump to navigation Jump to search

   Conversion of units is the conversion between different units of
   measurement for the same quantity, typically through multiplicative
   conversion factors.

Contents

     * 1 Techniques
          * 1.1 Process overview
          * 1.2 Conversion factors
          * 1.3 Software tools
          * 1.4 Calculation involving non-SI Units
               * 1.4.1 Calculate the pre-factor
               * 1.4.2 Calculate the numbers
     * 2 Tables of conversion factors
          * 2.1 Length
          * 2.2 Area
          * 2.3 Volume
          * 2.4 Plane angle
          * 2.5 Solid angle
          * 2.6 Mass
          * 2.7 Density
          * 2.8 Time
          * 2.9 Frequency
          * 2.10 Speed or velocity
          * 2.11 Flow (volume)
          * 2.12 Acceleration
          * 2.13 Force
          * 2.14 Pressure or mechanical stress
          * 2.15 Torque or moment of force
          * 2.16 Energy
          * 2.17 Power or heat flow rate
          * 2.18 Action
          * 2.19 Dynamic viscosity
          * 2.20 Kinematic viscosity
          * 2.21 Electric current
          * 2.22 Electric charge
          * 2.23 Electric dipole
          * 2.24 Electromotive force, electric potential difference
          * 2.25 Electrical resistance
          * 2.26 Capacitance
          * 2.27 Magnetic flux
          * 2.28 Magnetic flux density
          * 2.29 Inductance
          * 2.30 Temperature
          * 2.31 Information entropy
          * 2.32 Luminous intensity
          * 2.33 Luminance
          * 2.34 Luminous flux
          * 2.35 Illuminance
          * 2.36 Radiation – source activity
          * 2.37 Radiation – exposure
          * 2.38 Radiation – absorbed dose
          * 2.39 Radiation – equivalent dose
     * 3 See also
     * 4 Notes and references
     * 5 External links

Techniques[edit]

   See also: Dimensional analysis

  Process overview[edit]

   The process of conversion depends on the specific situation and the
   intended purpose. This may be governed by regulation, contract, technical
   specifications or other published standards. Engineering judgment may
   include such factors as:

     * The precision and accuracy of measurement and the associated
       uncertainty of measurement.
     * The statistical confidence interval or tolerance interval of the
       initial measurement.
     * The number of significant figures of the measurement.
     * The intended use of the measurement including the engineering
       tolerances.
     * Historical definitions of the units and their derivatives used in old
       measurements; e.g., international foot vs. US survey foot.

   Some conversions from one system of units to another need to be exact,
   without increasing or decreasing the precision of the first measurement.
   This is sometimes called soft conversion. It does not involve changing the
   physical configuration of the item being measured.

   By contrast, a hard conversion or an adaptive conversion may not be
   exactly equivalent. It changes the measurement to convenient and workable
   numbers and units in the new system. It sometimes involves a slightly
   different configuration, or size substitution, of the item.^[clarification
   needed] Nominal values are sometimes allowed and used.

  Conversion factors[edit]

   A conversion factor is used to change the units of a measured quantity
   without changing its value. The unity bracket method of unit
   conversion^[1] consists of a fraction in which the denominator is equal to
   the numerator, but they are in different units. Because of the identity
   property of multiplication, the value of a quantity will not change as
   long as it is multiplied by one.^[2] Also, if the numerator and
   denominator of a fraction are equal to each other, then the fraction is
   equal to one. So as long as the numerator and denominator of the fraction
   are equivalent, they will not affect the value of the measured quantity.

   The following example demonstrates how the unity bracket method^[3] is
   used to convert the rate 5 kilometers per second to meters per second. The
   symbols km, m, and s represent kilometer, meter, and second, respectively.

   {\displaystyle {\frac {5{\cancel {\text{km}}}}{\text{s}}}\cdot }
   {\displaystyle {\frac {{1000}{\text{ m}}}{{1}{\cancel {\text{ km}}}}}} =
   {\displaystyle {\frac {5000\cdot {\text{m}}}{{\text{s}}\cdot {1}}}=}
   {\displaystyle {\frac {5000{\text{ m}}}{\text{s}}}}

   Thus, it is found that 5 kilometers per second is equal to 5000 meters per
   second.

  Software tools[edit]

   There are many conversion tools. They are found in the function libraries
   of applications such as spreadsheets databases, in calculators, and in
   macro packages and plugins for many other applications such as the
   mathematical, scientific and technical applications.

   There are many standalone applications that offer the thousands of the
   various units with conversions. For example, the free software movement
   offers a command line utility GNU units for Linux and Windows.

  Calculation involving non-SI Units[edit]

   In the cases where non-SI units are used, the numerical calculation of a
   formula can be done by first working out the pre-factor, and then plug in
   the numerical values of the given/known quantities.

   For example, in the study of Bose–Einstein condensate,^[4] atomic mass m
   is usually given in daltons, instead of kilograms, and chemical potential
   μ is often given in Boltzmann constant times nanokelvin. The condensate's
   healing length is given by:

           {\displaystyle \xi ={\frac {\hbar }{\sqrt {2m\mu }}}\,.}

   For a ^23Na condensate with chemical potential of (Boltzmann constant
   times) 128 nK, the calculation of healing length (in micrometres) can be
   done in two steps:

    Calculate the pre-factor[edit]

   Assume that {\displaystyle m=1\,{\text{Da}},\mu =k_{\text{B}}\cdot
   1\,{\text{nK}}\,,} this gives

           {\displaystyle \xi ={\frac {\hbar }{\sqrt {2m\mu
           }}}=15.574\,\mathrm {\mu } m\,,}

   which is our pre-factor.

    Calculate the numbers[edit]

   Now, make use of the fact that {\displaystyle \xi \propto {\frac {1}{\sqrt
   {m\mu }}}}. With {\displaystyle m=23\,{\text{Da}},\mu
   =128\,k_{\text{B}}\cdot {\text{nK}}}, {\displaystyle \xi ={\frac
   {15.574}{\sqrt {23\cdot 128}}}\,\mathrm {\mu } m=0.287\,\mathrm {\mu } m}.

   This method is especially useful for programming and/or making a
   worksheet, where input quantities are taking multiple different values;
   For example, with the pre-factor calculated above, it's very easy to see
   that the healing length of ^174Yb with chemical potential 20.3 nK is
   {\displaystyle \xi ={\frac {15.574}{\sqrt {174\cdot 20.3}}}\,\mu
   m=0.262\,\mathrm {\mu } m}.

Tables of conversion factors[edit]

         This section needs additional citations for verification. Please     
         help improve this article by adding citations to reliable sources.   
   [IMG] Unsourced material may be challenged and removed.                    
         Find sources: "Conversion of units" – news · newspapers · books ·    
         scholar · JSTOR (January 2011) (Learn how and when to remove this    
         template message)                                                    

   This article gives lists of conversion factors for each of a number of
   physical quantities, which are listed in the index. For each physical
   quantity, a number of different units (some only of historical interest)
   are shown and expressed in terms of the corresponding SI unit. Conversions
   between units in the metric system are defined by their prefixes (for
   example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus
   not listed in this article. Exceptions are made if the unit is commonly
   known by another name (for example, 1 micron = 10^−6 metre). Within each
   table, the units are listed alphabetically, and the SI units (base or
   derived) are highlighted.

                                     Legend
   Symbol Definition                                                          
   ≡      exactly equal                                                       
   ≈      approximately equal to                                              
   ≘      (exactly) corresponds to (different types of quantity describing    
          the same phenomenon)                                                
   digits indicates that digits repeat infinitely (e.g. 8.294369 corresponds  
          to 8.294369369369369...)                                            
   (H)    of chiefly historical interest                                      

  Length[edit]

                                     Length
Name of unit       Symbol Definition                   Relation to SI units          
ångström           Å      ≡ 1×10^−10 m                 ≡ 0.1 nm                      
astronomical unit  au     ≡ 149597870700 m             ≡ 149597870700 m ^[5]         
                          ≈ Distance from Earth to Sun 
attometre          am     ≡ 1×10^−18 m                 ≡ 1×10^−18 m                  
barleycorn (H)            = 1⁄3 in (see note above     = 8.46×10^−3 m                
                          about rounding)              
bohr, atomic unit  a_0    = Bohr radius of hydrogen    ≈                             
of length                                              5.2917721092(17)×10^−11 m^[6] 
cable length              ≡ 608 ft                     ≈ 185.3184 m                  
(imperial)         
                          ≡                                                          
cable length              Link:                        ≡ 185.2 m
(International)           mw-deduplicated-inline-style 
                          1⁄10 nmi                     
cable length (US)         ≡ 720 ft                     = 219.456 m                   
chain (Gunter's;   ch     ≡ 66 ft (US) ≡ 4 rods^[7]    ≈ 20.11684 m                  
Surveyor's)        
cubit (H)                 ≡ Distance from fingers to   ≈ 0.5 m                       
                          elbow ≈ 18 in                
ell (H)            ell    ≡ 45 in ^[8] (In England     = 1.143 m                     
                          usually)                     
fathom             ftm    ≡ 6 ft ^[8]                  = 1.8288 m                    
femtometre         fm     ≡ 1×10^−15 m                 ≡ 1×10^−15 m                  
fermi              fm     ≡ 1×10^−15 m^[8]             ≡ 1×10^−15 m                  
                          ≡                                                          
finger                    Link:                        = 0.022225 m
                          mw-deduplicated-inline-style 
                          7⁄8 in                       
                          ≡                                                          
finger (cloth)            Link:                        = 0.1143 m
                          mw-deduplicated-inline-style 
                          4+1⁄2 in                     
foot (Benoît) (H)  ft                                  ≈ 0.304799735 m               
                   (Ben)  
foot (Cape) (H)           Legally defined as 1.033     ≈ 0.314858 m                  
                          English feet in 1859         
foot (Clarke's)    ft                                  ≈ 0.3047972654 m              
(H)                (Cla)  
foot (Indian) (H)  ft Ind                              ≈ 0.304799514 m               
foot, metric       mf     ≡ 300 mm                     ≡ 0.3 m                       
foot, metric              ≡                                                          
(Mesures usuelles)        Link:                        ≡ 0.3 m
(H)                       mw-deduplicated-inline-style 
                          1⁄3 m                        
                          ≡ 0.3048 m ≡                                               
foot               ft     Link:                        ≡ 0.3048 m
(International)           mw-deduplicated-inline-style 
                          1⁄3 yd ≡ 12 inches           
foot (Sear's) (H)  ft                                  ≈ 0.30479947 m                
                   (Sear) 
                          ≡                                                          
foot (US Survey)   ft     Link:                        ≈ 0.304800610 m
                   (US)   mw-deduplicated-inline-style 
                          1200⁄3937 m ^[9]             
                          ≡                                                          
french; charriere  F      Link:                        = 0.3 ×10^−3 m
                          mw-deduplicated-inline-style 
                          1⁄3 mm                       
furlong            fur    ≡ 10 chains = 660 ft = 220   = 201.168 m                   
                          yd ^[8]                      
hand                      ≡ 4 in ^[8]                  ≡ 0.1016 m                    
                          ≡ 2.54 cm ≡                                                
                          Link:                        
inch                      mw-deduplicated-inline-style 
(International)    in     1⁄36 yd ≡                    ≡ 0.0254 m
                          Link:                        
                          mw-deduplicated-inline-style 
                          1⁄12 ft                      
                          ≈ 1 hour walk, Currently                                   
league (land)      lea    defined in US as 3 Statute   ≈ 4828 m
                          miles,^[7] but historically  
                          varied from 2 to 9 km        
light-day                 ≡ 24 light-hours             ≡ 2.59020683712×10^13 m       
light-hour                ≡ 60 light-minutes           ≡ 1.0792528488×10^12 m        
light-minute              ≡ 60 light-seconds           ≡ 1.798754748×10^10 m         
light-second              ≡ Distance light travels in  ≡ 299792458 m                 
                          one second in vacuum         
light-year         ly     ≡ Distance light travels in  ≡ 9.4607304725808×10^15 m     
                          vacuum in 365.25 days ^[10]  
                          ≡                                                          
line               ln     Link:                        = 0.002116 m
                          mw-deduplicated-inline-style 
                          1⁄12 in ^[11]                
                          ≡                                                          
link (Gunter's;           Link:                        
Surveyor's)        lnk    mw-deduplicated-inline-style ≈ 0.2011684 m
                          1⁄100 ch ^[8] ≡ 0.66 ft (US) 
                          ≡ 7.92 in                    
link (Ramsden's;   lnk    ≡ 1 ft ^[8]                  = 0.3048 m                    
Engineer's)        
                          ≡ Distance light travels in                                
metre (SI base            Link:                        
unit)              m      mw-deduplicated-inline-style (SI base unit)
(meter)                   1⁄299792458 of a second in   
                          vacuum.^[12]                 
                          ≡                                                          
mickey                    Link:                        = 1.27×10^−4 m
                          mw-deduplicated-inline-style 
                          1⁄200 in                     
micrometre (old:   μ; μm  ≡ 1×10^−6 m                  ≡ 1×10^−6 m                   
micron)            
mil; thou          mil    ≡ 1×10^−3 in                 = 2.54×10^−5 m                
mil (Sweden and    mil    ≡ 10 km                      = 10000 m                     
Norway)            
mile                      ≡ 6082 ft                    = 1853.7936 m                 
(geographical) (H) 
mile               mi     ≡ 80 chains ≡ 5280 ft ≡      ≡ 1609.344 m                  
(international)           1760 yd                      
mile (tactical or         ≡ 6000 ft                    ≡ 1828.8 m                    
data)              
mile (telegraph)   mi     ≡ 6087 ft                    = 1855.3176 m                 
(H)                
                          ≡ 5280 US Survey feet ≡                                    
                          (5280 ×                      
mile (US Survey)   mi     Link:                        ≈ 1609.347219 m
                          mw-deduplicated-inline-style 
                          1200⁄3937) m                 
                          ≡                                                          
nail (cloth)              Link:                        = 0.05715 m
                          mw-deduplicated-inline-style 
                          2+1⁄4 in ^[8]                
nanometre          nm     ≡ 1×10^−9 m                  ≡ 1×10^−9 m                   
nautical league    NL; nl ≡ 3 nmi ^[8]                 = 5556 m                      
                   NM                                                                
nautical mile      (Adm); = 6080 ft                    = 1853.184 m
(Admiralty)        nmi    
                   (Adm)  
nautical mile      NM;    ≡ 1852 m^[13]                ≡ 1852 m                      
(international)    nmi    
nautical mile (US         ≡ 1853.248 m                 ≡ 1853.248 m                  
pre 1954)          
pace                      ≡ 2.5 ft ^[8]                = 0.762 m                     
palm                      ≡ 3 in ^[8]                  = 0.0762 m                    
                          Distant point with a                                       
                          parallax shift of one arc    
parsec             pc     second from a base of one    ≈ 30856775814913700 m^[16]
                          astronomical unit.           
                          ≡ 648000/π au^[14]^[15]      
pica                      ≡ 12 points                  Dependent on point measures.  
picometre          pm     ≡ 1×10^−12 m                 ≡ 1×10^−12 m                  
                          ≡                                                          
point (American,   pt     Link:                        ≈ 0.000351450 m
English)^[17]^[18]        mw-deduplicated-inline-style 
                          1⁄72.272 in                  
                          ≡                                                          
                          Link:                                                      
                          mw-deduplicated-inline-style                               
                          1⁄12 ×                                                     
                          Link:                        ≈ 0.00037597 m;
point (Didot;             mw-deduplicated-inline-style 
European)          pt     1⁄72 of pied du roi;         After 1878:
^[18]^[19]                                             ≈ 0.00037593985 m
                          After 1878:                  
                          ≡                            
                          Link:                        
                          mw-deduplicated-inline-style 
                          5⁄133 cm                     
                          ≡                                                          
point (PostScript) pt     Link:                        = 0.0003527 m
^[17]                     mw-deduplicated-inline-style 
                          1⁄72 in                      
                          ≡                                                          
point (TeX) ^[17]  pt     Link:                        = 0.0003514598 m
                          mw-deduplicated-inline-style 
                          1⁄72.27 in                   
                          ≡                                                          
quarter                   Link:                        = 0.2286 m
                          mw-deduplicated-inline-style 
                          1⁄4 yd                       
                          ≡                                                          
rod; pole; perch   rd     Link:                        = 5.0292 m
(H)                       mw-deduplicated-inline-style 
                          16+1⁄2 ft                    
rope (H)           rope   ≡ 20 ft ^[8]                 = 6.096 m                     
shaku (Japan)             ≡ 10/33 m                    ≈ 0.303 0303 m                
span (H)                  ≡ 9 in ^[8]                  = 0.2286 m                    
spat^[20]                                              ≡ 1×10^12 m                   
stick (H)                 ≡ 2 in                       = 0.0508 m                    
toise (French,     T      ≡ 27000/13853 m              ≈ 1.949 0363 m                
post 1667) (H)     
                          ≡                                                          
twip               twp    Link:                        = 1.7638×10^−5 m
                          mw-deduplicated-inline-style 
                          1⁄1440 in                    
x unit; siegbahn   xu                                  ≈ 1.0021×10^−13 m ^[8]        
yard               yd     ≡ 0.9144 m ^[9] ≡ 3 ft ≡ 36  ≡ 0.9144 m                    
(International)           in                           
yoctometre         ym     ≡ 1×10^−24 m                 ≡ 1×10^−24 m                  
zeptometre         zm     ≡ 1×10^−21 m                 ≡ 1×10^−21 m                  

  Area[edit]

                                      Area
Name of unit              Symbol Definition                   Relation to SI units      
acre (international)      ac     ≡ 1 ch × 10 ch = 4840 sq yd  ≡ 4046.8564224 m^2        
acre (US survey)          ac     ≡ 10 sq ch = 4840 sq yd,     ≈ 4046.873 m^2^[21]       
                                 also 43560 sq ft             
are                       a      ≡ 100 m^2                    ≡ 100 m^2                 
barn                      b      ≡ 10^−28 m^2                 ≡ 10^−28 m^2              
barony                           ≡ 4000 ac                    ≡ 1.61874256896×10^7 m^2  
board                     bd     ≡ 1 in × 1 ft                ≡ 7.74192×10^−3 m^2       
boiler horsepower         bhp    ≡ 1 ft^2 × 1 bhp /                                     
equivalent direct         EDR    (240 BTU_IT/h)               ≈ 12.958174 m^2
radiation                 
                                 ≡                                                      
circular inch             circ   Link:                        ≈ 5.067075×10^−4 m^2
                          in     mw-deduplicated-inline-style 
                                 π⁄4 sq in                    
                                 ≡                                                      
circular mil; circular    circ   Link:                        ≈ 5.067075×10^−10 m^2
thou                      mil    mw-deduplicated-inline-style 
                                 π⁄4 mil^2                    
cord                             ≡ 192 bd                     ≡ 1.48644864 m^2          
cuerda (PR Survey)        cda    ≡ 1 cda x 1 cda = 0.971222   ≡ 3930.395625 m^2         
                                 acre                         
dunam                            ≡ 1000 m^2                   ≡ 1000 m^2                
guntha (India)                   ≡ 121 sq yd                  ≈ 101.17 m^2              
hectare                   ha     ≡ 10000 m^2                  ≡ 10000 m^2               
hide                             ≈ 120 ac (variable)          ≈ 5×10^5 m^2              
                                 ≡                                                      
rood                      ro     Link:                        = 1011.7141056 m^2
                                 mw-deduplicated-inline-style 
                                 1⁄4 ac                       
                                 ≡                                                      
                                 Link:                        
                                 mw-deduplicated-inline-style 
ping                             20⁄11 m ×                    ≈ 3.306 m^2
                                 Link:                        
                                 mw-deduplicated-inline-style 
                                 20⁄11 m                      
section                          ≡ 1 mi × 1 mi                = 2.589988110336×10^6 m^2 
shed                             ≡ 10^−52 m^2                 = 10^−52 m^2              
square (roofing)                 ≡ 10 ft × 10 ft              = 9.290304 m^2            
                                 ≡ 66 ft × 66 ft =                                      
square chain              sq ch  Link:                        ≡ 404.68564224 m^2
(international)                  mw-deduplicated-inline-style 
                                 1⁄10 ac                      
                                 ≡ 66 ft (US) × 66 ft (US) =                            
square chain (US Survey)  sq ch  Link:                        ≈ 404.6873 m^2
                                 mw-deduplicated-inline-style 
                                 1⁄10 US survey acre          
square foot               sq ft  ≡ 1 ft × 1 ft                ≡ 9.290304×10^−2 m^2      
square foot (US Survey)   sq ft  ≡ 1 ft (US) × 1 ft (US)      ≈                         
                                                              9.2903411613275×10^−2 m^2 
square inch               sq in  ≡ 1 in × 1 in                ≡ 6.4516×10^−4 m^2        
square kilometre          km^2   ≡ 1 km × 1 km                = 10^6 m^2                
square link               sq lnk ≡ 1 lnk × 1 lnk ≡ 0.66 ft ×  = 4.0468564224×10^−2 m^2  
(Gunter's)(International)        0.66 ft                      
square link (Gunter's)(US sq lnk ≡ 1 lnk × 1 lnk ≡ 0.66 ft    ≈ 4.046872×10^−2 m^2      
Survey)                          (US) × 0.66 ft (US)          
square link (Ramsden's)   sq lnk ≡ 1 lnk × 1 lnk ≡ 1 ft ×     = 0.09290304 m^2          
                                 1 ft                         
square metre (SI unit)    m^2    ≡ 1 m × 1 m                  = 1 m^2                   
square mil; square thou   sq mil ≡ 1 mil × 1 mil              = 6.4516×10^−10 m^2       
square mile               sq mi  ≡ 1 mi × 1 mi                ≡ 2.589988110336×10^6 m^2 
square mile (US Survey)   sq mi  ≡ 1 mi (US) × 1 mi (US)      ≈ 2.58999847×10^6 m^2     
square rod/pole/perch     sq rd  ≡ 1 rd × 1 rd                = 25.29285264 m^2         
square yard               sq yd  ≡ 1 yd × 1 yd                ≡ 0.83612736 m^2          
(International)           
stremma                          ≡ 1000 m^2                   = 1000 m^2                
township                         ≡ 36 sq mi (US)              ≈ 9.323994×10^7 m^2       
yardland                         ≈ 30 ac                      ≈ 1.2×10^5 m^2            

  Volume[edit]

                                     Volume
   Name of unit   Symbol Definition                   Relation to SI units       
   acre-foot      ac ft  ≡ 1 ac x 1 ft = 43560 cu ft  = 1233.48183754752 m^3     
   acre-inch             ≡ 1 ac × 1 in                = 102.79015312896 m^3      
   barrel         bl     ≡ 36 gal (imp)               = 0.16365924 m^3           
   (imperial)     (imp)  
   barrel                                                                        
   (petroleum);   bl;    ≡ 42 gal (US)                ≡ 0.158987294928 m^3
   archaic        bbl
   blue-barrel    
   barrel (US     bl     ≡ 105 qt (US) = 105/32 bu    = 0.115628198985075 m^3    
   dry)           (US)   (US lvl)                     
                         ≡                                                       
   barrel (US     fl bl  Link:                        = 0.119240471196 m^3
   fluid)         (US)   mw-deduplicated-inline-style 
                         31+1⁄2 gal (US)              
   board-foot     bdft   ≡ 144 cu in                  ≡ 2.359737216×10^−3 m^3    
   bucket         bkt    ≡ 4 gal (imp)                = 0.01818436 m^3           
   (imperial)     
   bushel         bu     ≡ 8 gal (imp)                = 0.03636872 m^3           
   (imperial)     (imp)  
                         ≡                                                       
   bushel (US dry bu     Link:                        = 0.0440488377086 m^3
   heaped)        (US)   mw-deduplicated-inline-style 
                         1+1⁄4 bu (US lvl)            
   bushel (US dry bu (US ≡ 2150.42 cu in              = 0.03523907016688 m^3     
   level)         lvl)   
   butt, pipe            ≡ 126 gal (US) (wine)        = 0.476961884784 m^3       
   coomb                 ≡ 4 bu (imp)                 = 0.14547488 m^3           
   cord                  ≡ 8 ft × 4 ft × 4 ft         = 3.624556363776 m^3       
   (firewood)     
   cord-foot             ≡ 16 cu ft                   = 0.453069545472 m^3       
   cubic fathom   cu fm  ≡ 1 fm × 1 fm × 1 fm         = 6.116438863872 m^3       
   cubic foot     ft^3   ≡ 1 ft × 1 ft × 1 ft         ≡ 0.028316846592 m^3       
   cubic inch     in^3   ≡ 1 in × 1 in × 1 in         ≡ 16.387064×10^−6 m^3      
   cubic metre    m^3    ≡ 1 m × 1 m × 1 m            ≡ 1 m^3                    
   (SI unit)      
   cubic mile     cu mi  ≡ 1 mi × 1 mi × 1 mi         ≡ 4168181825.440579584 m^3 
   cubic yard     yd^3   ≡ 27 cu ft                   ≡ 0.764554857984 m^3       
   cup                   ≡ 10 fl oz (imp)             = 284.130625×10^−6 m^3     
   (breakfast)    
   cup (Canadian) c (CA) ≡ 8 fl oz (imp)              = 227.3045×10^−6 m^3       
   cup (metric)   c      ≡ 250.0×10^−6 m^3            ≡ 250.0×10^−6 m^3          
                         ≡ 8 US fl oz ≡                                          
   cup (US        c (US) Link:                        = 236.5882365×10^−6 m^3
   customary)            mw-deduplicated-inline-style 
                         1⁄16 gal (US)                
   cup (US food                                                                  
   nutrition      c (US) ≡ 240 mL^[22]                = 2.4×10^−4 m^3
   labeling)      
                         ≡                                                       
                         Link:                                                   
   dash                  mw-deduplicated-inline-style = 369.961751302083×10^−9
   (imperial)            1⁄384 gi (imp) =             m^3
                         Link:                        
                         mw-deduplicated-inline-style 
                         1⁄2 pinch (imp)              
                         ≡                                                       
                         Link:                                                   
                         mw-deduplicated-inline-style =
   dash (US)             1⁄96 US fl oz =              308.057599609375×10^−9 m^3
                         Link:                        
                         mw-deduplicated-inline-style 
                         1⁄2 US pinch                 
                         ≡                                                       
   dessertspoon          Link:                        = 11.8387760416×10^−6 m^3
   (imperial)            mw-deduplicated-inline-style 
                         1⁄12 gi (imp)                
                         ≡                                                       
   drop           gtt    Link:                        = 98.6564670138×10^−9 m^3
   (imperial)            mw-deduplicated-inline-style 
                         1⁄288 fl oz (imp)            
   drop                  ≡                                                       
   (imperial)     gtt    Link:                        ≈ 77.886684×10^−9 m^3
   (alt)                 mw-deduplicated-inline-style 
                         1⁄1824 gi (imp)              
                         ≡                                                       
   drop (medical)        Link:                        = 83.3×10^−9 m^3
                         mw-deduplicated-inline-style 
                         1⁄12 mL                      
                         ≡                                                       
   drop (metric)         Link:                        = 50.0×10^−9 m^3
                         mw-deduplicated-inline-style 
                         1⁄20 mL                      
                         ≡                                                       
   drop (US)      gtt    Link:                        = 82.14869322916×10^−9 m^3
                         mw-deduplicated-inline-style 
                         1⁄360 US fl oz               
                         ≡                                                       
   drop (US)      gtt    Link:                        ≈ 64.85423149671×10^−9 m^3
   (alt)                 mw-deduplicated-inline-style 
                         1⁄456 US fl oz               
                         ≡                                                       
   drop (US)      gtt    Link:                        ≈ 51.34293326823×10^−9 m^3
   (alt)                 mw-deduplicated-inline-style 
                         1⁄576 US fl oz               
                         ≡                                                       
   fifth                 Link:                        = 757.0823568×10^−6 m^3
                         mw-deduplicated-inline-style 
                         1⁄5 US gal                   
   firkin                ≡ 9 gal (imp)                = 0.04091481 m^3           
                         ≡                                                       
   fluid drachm   fl dr  Link:                        = 3.5516328125×10^−6 m^3
   (imperial)            mw-deduplicated-inline-style 
                         1⁄8 fl oz (imp)              
   fluid dram            ≡                                                       
   (US); US       fl dr  Link:                        =                          
   fluidram              mw-deduplicated-inline-style 3.6966911953125×10^−6 m^3
                         1⁄8 US fl oz                 
                         ≡                                                       
   fluid scruple  fl s   Link:                        = 1.18387760416×10^−6 m^3
   (imperial)            mw-deduplicated-inline-style 
                         1⁄24 fl oz (imp)             
   gallon (beer)  beer   ≡ 282 cu in                  = 4.621152048×10^−3 m^3    
                  gal    
   gallon         gal    ≡ 4.54609 L                  ≡ 4.54609×10^−3 m^3        
   (imperial)     (imp)  
                         ≡                                                       
   gallon (US     gal    Link:                        = 4.40488377086×10^−3 m^3
   dry)           (US)   mw-deduplicated-inline-style 
                         1⁄8 bu (US lvl)              
   gallon (US     gal    ≡ 231 cu in                  ≡ 3.785411784×10^−3 m^3    
   fluid; Wine)   (US)   
   gill           gi                                                             
   (imperial);    (imp); ≡ 5 fl oz (imp)              = 142.0653125×10^−6 m^3
   Noggin         nog    
   gill (US)      gi     ≡ 4 US fl oz                 = 118.29411825×10^−6 m^3   
                  (US)   
   hogshead       hhd    ≡ 2 bl (imp)                 = 0.32731848 m^3           
   (imperial)     (imp)  
   hogshead (US)  hhd    ≡ 2 fl bl (US)               = 0.238480942392 m^3       
                  (US)   
                         ≡                                                       
   jigger                Link:                        ≈ 44.36×10^−6 m^3
   (bartending)          mw-deduplicated-inline-style 
                         1+1⁄2 US fl oz               
   kilderkin             ≡ 18 gal (imp)               = 0.08182962 m^3           
   lambda         λ      ≡ 1 mm^3                     = 1×10^−9 m^3              
   last                  ≡ 80 bu (imp)                = 2.9094976 m^3            
   litre          L or l ≡ 1 dm^3 ^[23]               ≡ 0.001 m^3                
   (liter)        
   load                  ≡ 50 cu ft                   = 1.4158423296 m^3         
                         ≡                                                       
   minim                 Link:                        
   (imperial)     min    mw-deduplicated-inline-style = 59.1938802083×10^−9 m^3
                         1⁄480 fl oz (imp) = 1/60 fl  
                         dr (imp)                     
                         ≡                                                       
                         Link:                                                   
                         mw-deduplicated-inline-style =
   minim (US)     min    1⁄480 US fl oz =             61.611519921875×10^−9 m^3
                         Link:                        
                         mw-deduplicated-inline-style 
                         1⁄60 US fl dr                
                         ≡                                                       
   ounce (fluid   fl oz  Link:                        ≡ 28.4130625×10^−6 m^3
   imperial)      (imp)  mw-deduplicated-inline-style 
                         1⁄160 gal (imp)              
                         ≡                                                       
   ounce (fluid   US fl  Link:                        ≡ 29.5735295625×10^−6 m^3
   US customary)  oz     mw-deduplicated-inline-style 
                         1⁄128 gal (US)               
   ounce (fluid                                                                  
   US food        US fl  ≡ 30 mL^[22]                 ≡ 3×10^−5 m^3
   nutrition      oz
   labeling)      
   peck           pk     ≡ 2 gal (imp)                = 9.09218×10^−3 m^3        
   (imperial)     
                         ≡                                                       
   peck (US dry)  pk     Link:                        = 8.80976754172×10^−3 m^3
                         mw-deduplicated-inline-style 
                         1⁄4 US lvl bu                
                         ≡                                                       
                         Link:                        
                         mw-deduplicated-inline-style 
   perch          per    16+1⁄2 ft ×                  = 0.700841953152 m^3
                         Link:                        
                         mw-deduplicated-inline-style 
                         1+1⁄2 ft × 1 ft              
                         ≡                                                       
   pinch                 Link:                        = 739.92350260416×10^−9    
   (imperial)            mw-deduplicated-inline-style m^3
                         1⁄192 gi (imp) = 1/16 tsp    
                         (imp)                        
                         ≡                                                       
   pinch (US)            Link:                        =                          
                         mw-deduplicated-inline-style 616.11519921875×10^−9 m^3
                         1⁄48 US fl oz = 1/16 US tsp  
                         ≡                                                       
   pint           pt     Link:                        = 568.26125×10^−6 m^3
   (imperial)     (imp)  mw-deduplicated-inline-style 
                         1⁄8 gal (imp)                
                         ≡                                                       
                         Link:                        
                  pt (US mw-deduplicated-inline-style 
   pint (US dry)  dry)   1⁄64 bu (US lvl) ≡           = 550.6104713575×10^−6 m^3
                         Link:                        
                         mw-deduplicated-inline-style 
                         1⁄8 gal (US dry)             
                         ≡                                                       
   pint (US       pt (US Link:                        = 473.176473×10^−6 m^3
   fluid)         fl)    mw-deduplicated-inline-style 
                         1⁄8 gal (US)                 
                         ≡                                                       
   pony                  Link:                        =                          
                         mw-deduplicated-inline-style 22.180147171875×10^−6 m^3
                         3⁄4 US fl oz                 
                         ≡                                                       
   pottle;               Link:                        
   quartern              mw-deduplicated-inline-style = 2.273045×10^−3 m^3
                         1⁄2 gal (imp) = 80 fl oz     
                         (imp)                        
                         ≡                                                       
   quart          qt     Link:                        = 1.1365225×10^−3 m^3
   (imperial)     (imp)  mw-deduplicated-inline-style 
                         1⁄4 gal (imp)                
                         ≡                                                       
                         Link:                        
                  qt     mw-deduplicated-inline-style 
   quart (US dry) (US)   1⁄32 bu (US lvl) =           = 1.101220942715×10^−3 m^3
                         Link:                        
                         mw-deduplicated-inline-style 
                         1⁄4 gal (US dry)             
                         ≡                                                       
   quart (US      qt     Link:                        = 946.352946×10^−6 m^3
   fluid)         (US)   mw-deduplicated-inline-style 
                         1⁄4 gal (US fl)              
   quarter; pail         ≡ 8 bu (imp)                 = 0.29094976 m^3           
   register ton          ≡ 100 cu ft                  = 2.8316846592 m^3         
   sack (US)             ≡ 3 bu (US lvl)              = 0.10571721050064 m^3     
   seam                  ≡ 8 bu ^[20]                 = 0.29095 m^3              
   shot (US)             usually 1.5 US fl oz^[20]    ≈ 44.4×10^−6 m^3           
   strike                ≡ 2 bu (imp)                 = 0.07273744 m^3           
   (imperial)     
   strike (US)           ≡ 2 bu (US lvl)              = 0.07047814033376 m^3     
   tablespoon                                                                    
   (Australian                                        ≡ 20.0×10^−6 m^3
   metric)        
                         ≡                                                       
   tablespoon     tbsp   Link:                        = 14.20653125×10^−6 m^3
   (Canadian)            mw-deduplicated-inline-style 
                         1⁄2 fl oz (imp)              
                         ≡                                                       
   tablespoon     tbsp   Link:                        = 17.7581640625×10^−6 m^3
   (imperial)            mw-deduplicated-inline-style 
                         5⁄8 fl oz (imp)              
   tablespoon                                         ≡ 15×10^−6 m^3             
   (metric)       
                         ≡                                                       
   tablespoon (US tbsp   Link:                        = 14.78676478125×10^−6 m^3
   customary)            mw-deduplicated-inline-style 
                         1⁄2 US fl oz                 
   tablespoon (US                                                                
   food nutrition tbsp   ≡ 15 mL^[22]                 = 15×10^−6 m^3
   labeling)      
                         ≡                                                       
   teaspoon       tsp    Link:                        = 4.735510416×10^−6 m^3
   (Canadian)            mw-deduplicated-inline-style 
                         1⁄6 fl oz (imp)              
                         ≡                                                       
   teaspoon       tsp    Link:                        = 5.91938802083×10^−6 m^3
   (imperial)            mw-deduplicated-inline-style 
                         1⁄24 gi (imp)                
   teaspoon              ≡ 5.0×10^−6 m^3              ≡ 5.0×10^−6 m^3            
   (metric)       
                         ≡                                                       
   teaspoon (US   tsp    Link:                        = 4.92892159375×10^−6 m^3
   customary)            mw-deduplicated-inline-style 
                         1⁄6 US fl oz                 
   teaspoon (US                                                                  
   food nutrition tsp    ≡ 5 mL^[22]                  = 5×10^−6 m^3
   labeling)      
   timber foot           ≡ 1 cu ft                    = 0.028316846592 m^3       
   ton                   ≡ 35 cu ft                   = 0.99108963072 m^3        
   (displacement) 
   ton (freight)         ≡ 40 cu ft                   = 1.13267386368 m^3        
   ton (water)           ≡ 28 bu (imp)                = 1.01832416 m^3           
   tun                   ≡ 252 gal (wine)             = 0.953923769568 m^3       
   wey (US)              ≡ 40 bu (US lvl)             = 1.4095628066752 m^3      

  Plane angle[edit]

                                  Plane angle
   Name of unit Symbol    Definition                     Relation to SI units 
                          ≡                                                   
   NATO mil     (various) Link:                          ≈ 0.981748×10^−3 rad
                          mw-deduplicated-inline-style   
                          2π⁄6400 rad                    
                          ≡                                                   
   Swedish                Link:                          ≈ 0.997302×10^−3 rad
   streck                 mw-deduplicated-inline-style   
                          2π⁄6300 rad                    
                          ≡                                                   
   milliradian  mrad      Link:                          ≈ 1×10^−3 rad
                          mw-deduplicated-inline-style   
                          1⁄1000 rad                     
                          ≡                                                   
   Warsaw Pact            Link:                          ≈ 1.047167×10^−3 rad
   mil                    mw-deduplicated-inline-style   
                          2π⁄6000 rad                    
                          ≡                                                   
   arcminute;   '         Link:                          ≈ 0.290888×10^−3 rad
   MOA                    mw-deduplicated-inline-style   
                          1°⁄60                          
                          ≡                                                   
   arcsecond    "         Link:                          ≈ 4.848137×10^−6 rad
                          mw-deduplicated-inline-style   
                          1°⁄3600                        
   centesimal             ≡                                                   
   minute of    '         Link:                          ≈ 0.157080×10^−3 rad
   arc                    mw-deduplicated-inline-style   
                          1⁄100 grad                     
   centesimal             ≡                                                   
   second of    "         Link:                          ≈ 1.570796×10^−6 rad
   arc                    mw-deduplicated-inline-style   
                          1⁄10000 grad                   
                          ≡                                                   
                          Link:                                               
   degree (of             mw-deduplicated-inline-style   ≈
   arc)         °         1⁄360 of a revolution ≡        17.453293×10^−3 rad
                          Link:                          
                          mw-deduplicated-inline-style   
                          π⁄180 rad                      
                          ≡                                                   
                          Link:                                               
   grad;                  mw-deduplicated-inline-style   ≈
   gradian; gon grad      1⁄400 of a revolution ≡        15.707963×10^−3 rad
                          Link:                          
                          mw-deduplicated-inline-style   
                          π⁄200 rad ≡ 0.9°               
   octant                 ≡ 45°                          ≈ 0.785398 rad       
   quadrant               ≡ 90°                          ≈ 1.570796 rad       
                          The angle subtended at the                          
                          center of a circle by an arc   
   radian       rad       whose length is equal to the   = 1 rad
   (SI unit)              circle's radius.               
                          One full revolution            
                          encompasses 2π radians.        
   sextant                ≡ 60°                          ≈ 1.047198 rad       
   sign                   ≡ 30°                          ≈ 0.523599 rad       

  Solid angle[edit]

                                  Solid angle
   Name of unit Symbol   Definition                           Relation to SI  
                                                              units           
   spat                  ≡ 4π sr^[20] – The solid angle       ≈ 12.56637 sr   
                         subtended by a sphere at its centre. 
   square       deg^2;   ≡ (                                  ≈ 0.30462×10^−3 
   degree       sq.deg.; Link: mw-deduplicated-inline-style   sr              
                (°)^2    π⁄180)^2 sr                          
                         The solid angle subtended at the                     
   steradian             center of a sphere of radius r by a  
   (SI unit)    sr       portion of the surface of the sphere = 1 sr
                         having an area r^2.                  
                         A sphere subtends 4π sr.^[20]        

  Mass[edit]

   Notes:

     * See Weight for detail of mass/weight distinction and conversion.
     * Avoirdupois is a system of mass based on a pound of 16 ounces, while
       Troy weight is the system of mass where 12 troy ounces equals one troy
       pound.
     * In this table, the symbol g_0 is used to denote standard gravity in
       order to avoid confusion with the (upright) g symbol for gram.

                                      Mass
 Name of unit  Symbol Definition                   Relation to SI units          
 atomic mass   u; AMU Same as dalton (see below)   ≈                             
 unit, unified                                     1.660539040(20)×10^−27 kg^[7] 
 atomic unit                                                                     
 of mass,      m_e                                 ≈                             
 electron rest                                     9.10938291(40)×10^−31 kg^[24]
 mass          
 bag (coffee)         ≡ 60 kg                      = 60 kg                       
 bag (Portland        ≡ 94 lb av                   = 42.63768278 kg              
 cement)       
                      ≡                                                          
 barge                Link:                        = 20411.65665 kg
                      mw-deduplicated-inline-style 
                      22+1⁄2 short ton             
                      ≡                                                          
 carat         kt     Link:                        = 205.1965483 mg
                      mw-deduplicated-inline-style 
                      3+1⁄6 gr                     
 carat         ct     ≡ 200 mg                     = 200 mg                      
 (metric)      
 clove                ≡ 8 lb av                    = 3.62873896 kg               
 crith                ≡ mass of 1 L of hydrogen    ≈ 89.9349 mg                  
                      gas at STP                   
                      1/12 the mass of an unbound                                
 dalton        Da     neutral atom of carbon-12 in ≈                             
                      its nuclear and electronic   1.660538921(73)×10^−27 kg^[7]
                      ground state and at rest     
 dram                                                                            
 (apothecary;  dr t   ≡ 60 gr                      = 3.8879346 g
 troy)         
                      ≡                                                          
 dram          dr av  Link:                        = 1.7718451953125 g
 (avoirdupois)        mw-deduplicated-inline-style 
                      27+11⁄32 gr                  
 electronvolt  eV     ≡ 1 eV (energy unit) / c^2   =                             
                                                   1.78266184(45)×10^−36 kg^[7]  
 gamma         γ      ≡ 1 μg                       = 1 μg                        
                      ≡                                                          
 grain         gr     Link:                        ≡ 64.79891 mg
                      mw-deduplicated-inline-style 
                      1⁄7000 lb av                 
 grave         gv     grave was the original name  ≡ 1 kg                        
                      of the kilogram              
 hundredweight long                                                              
 (long)        cwt or ≡ 112 lb av                  = 50.80234544 kg
               cwt    
 hundredweight                                                                   
 (short);      sh cwt ≡ 100 lb av                  = 45.359237 kg
 cental        
 kilogram             ≈ mass of the prototype near                               
 (kilogramme)  kg     Paris                        (SI base unit)^[12]
                      ≈ mass of 1 litre of water   
 kip           kip    ≡ 1000 lb av                 = 453.59237 kg                
 mark                 ≡ 8 oz t                     = 248.8278144 g               
                      ≡                                                          
 mite                 Link:                        = 3.2399455 mg
                      mw-deduplicated-inline-style 
                      1⁄20 gr                      
                      ≡                                                          
 mite (metric)        Link:                        = 50 mg
                      mw-deduplicated-inline-style 
                      1⁄20 g                       
 ounce                ≡                                                          
 (apothecary;  oz t   Link:                        = 31.1034768 g
 troy)                mw-deduplicated-inline-style 
                      1⁄12 lb t                    
                      ≡                                                          
 ounce         oz av  Link:                        = 28.349523125 g
 (avoirdupois)        mw-deduplicated-inline-style 
                      1⁄16 lb                      
 ounce (US                                                                       
 food          oz     ≡ 28 g^[22]                  = 28 g
 nutrition     
 labelling)    
                      ≡                                                          
 pennyweight   dwt;   Link:                        = 1.55517384 g
               pwt    mw-deduplicated-inline-style 
                      1⁄20 oz t                    
                      ≡                                                          
 point                Link:                        = 2 mg
                      mw-deduplicated-inline-style 
                      1⁄100 ct                     
 pound         lb av  ≡ 0.45359237 kg = 7000       ≡ 0.45359237 kg               
 (avoirdupois)        grains                       
 pound                ≡ 500 g                      = 500 g                       
 (metric)      
 pound (troy)  lb t   ≡ 5760 grains                = 0.3732417216 kg             
                      ≡                                                          
 quarter              Link:                        
 (imperial)           mw-deduplicated-inline-style = 12.70058636 kg
                      1⁄4 long cwt = 2 st = 28 lb  
                      av                           
                      ≡                                                          
 quarter              Link:                        = 226.796185 kg
 (informal)           mw-deduplicated-inline-style 
                      1⁄4 short ton                
                      ≡                                                          
 quarter, long        Link:                        = 254.0117272 kg
 (informal)           mw-deduplicated-inline-style 
                      1⁄4 long ton                 
 quintal       q      ≡ 100 kg                     = 100 kg                      
 (metric)      
 scruple       s ap   ≡ 20 gr                      = 1.2959782 g                 
 (apothecary)  
                      ≡                                                          
 sheet                Link:                        = 647.9891 mg
                      mw-deduplicated-inline-style 
                      1⁄700 lb av                  
 slug;         slug   ≡ g_0 × 1 lb av × 1 s^2/ft   ≈ 14.593903 kg                
 geepound; hyl 
 stone         st     ≡ 14 lb av                   = 6.35029318 kg               
 ton, assay    AT     ≡ 1 mg × 1 long ton ÷ 1 oz t = 32.6 g                      
 (long)        
 ton, assay    AT     ≡ 1 mg × 1 short ton ÷ 1 oz  = 29.16 g                     
 (short)              t                            
               long                                                              
 ton, long     tn or  ≡ 2240 lb                    = 1016.0469088 kg
               ton    
 ton, short    sh tn  ≡ 2000 lb                    = 907.18474 kg                
 tonne (mts    t      ≡ 1000 kg                    = 1000 kg                     
 unit)         
 wey                  ≡ 252 lb = 18 st             = 114.30527724 kg (variants   
                                                   exist)                        
 Zentner       Ztr.   Definitions vary.^[20]^[25]  

  Density[edit]

                                    Density
   Name of unit               Symbol    Definition  Relation to SI units      
   gram per millilitre        g/mL      ≡ g/mL      = 1000 kg/m^3             
   kilogram per cubic metre   kg/m^3    ≡ kg/m^3    = 1 kg/m^3                
   (SI unit)                  
   kilogram per litre         kg/L      ≡ kg/L      = 1000 kg/m^3             
   ounce (avoirdupois) per    oz/ft^3   ≡ oz/ft^3   ≈ 1.001153961 kg/m^3      
   cubic foot                 
   ounce (avoirdupois) per    oz/in^3   ≡ oz/in^3   ≈ 1.729994044×10^3 kg/m^3 
   cubic inch                 
   ounce (avoirdupois) per    oz/gal    ≡ oz/gal    ≈ 6.236023291 kg/m^3      
   gallon (imperial)          
   ounce (avoirdupois) per    oz/gal    ≡ oz/gal    ≈ 7.489151707 kg/m^3      
   gallon (US fluid)          
   pound (avoirdupois) per    lb/ft^3   ≡ lb/ft^3   ≈ 16.01846337 kg/m^3      
   cubic foot                 
   pound (avoirdupois) per    lb/in^3   ≡ lb/in^3   ≈ 2.767990471×10^4 kg/m^3 
   cubic inch                 
   pound (avoirdupois) per    lb/gal    ≡ lb/gal    ≈ 99.77637266 kg/m^3      
   gallon (imperial)          
   pound (avoirdupois) per    lb/gal    ≡ lb/gal    ≈ 119.8264273 kg/m^3      
   gallon (US fluid)          
   slug per cubic foot        slug/ft^3 ≡ slug/ft^3 ≈ 515.3788184 kg/m^3      

  Time[edit]

                                      Time
   Name of unit     Symbol Definition                   Relation to SI units  
   Atomic unit of   au     ≡ a_0/(α⋅c)                  ≈                     
   time                                                 2.418884254×10^−17 s  
   Callippic cycle         ≡ 441 mo (hollow) + 499 mo   = 2.396736 Gs or      
                           (full) = 76 a of 365.25 d    2.3983776 Gs^[note 1] 
   Century          c      ≡ 100 years (100 a)          = 3.1556952 Gs^[note  
                                                        2]^[note 3]           
   Day              d      = 24 h = 1440 min            = 86.4 ks^[note 3]    
                           ≡ Time needed for the Earth                        
                           to rotate once around its    
                           axis, determined from        
   Day (sidereal)   d      successive transits of a     ≈ 86.1641 ks
                           very distant astronomical    
                           object across an observer's  
                           meridian (International      
                           Celestial Reference Frame)   
   Decade           dec    ≡ 10 years (10 a)            = 315.569520 Ms^[note 
                                                        2]^[note 3]           
   Fortnight        fn     ≡ 2 wk                       = 1.2096 Ms^[note 3]  
                           ≡                                                  
   Helek                   Link:                        = 3.3 s
                           mw-deduplicated-inline-style 
                           1⁄1080 h                     
   Hipparchic cycle        ≡ 4 Callippic cycles - 1 d   = 9.593424 Gs         
   Hour             h      ≡ 60 min                     = 3.6 ks^[note 3]     
                           ≡                                                  
   Jiffy            j      Link:                        = 16.6 ms
                           mw-deduplicated-inline-style 
                           1⁄60 s                       
                           ≡                                                  
   Jiffy            ja     Link:                        = 10 ms
   (alternative)           mw-deduplicated-inline-style 
                           1⁄100 s                      
                           ≡                                                  
                           Link:                        
   Ke (quarter of          mw-deduplicated-inline-style 
   an hour)                1⁄4 h =                      = 900 s
                           Link:                        
                           mw-deduplicated-inline-style 
                           1⁄96 d = 15 min              
                           ≡                                                  
   Ke (traditional)        Link:                        = 864 s
                           mw-deduplicated-inline-style 
                           1⁄100 d = 14.4 min           
   Lustre; Lustrum         ≡ 5 a of 365 d^[note 4]      = 157.68 Ms           
   Metonic cycle;          ≡ 110 mo (hollow) + 125 mo   = 599.616 Ms          
   enneadecaeteris         (full) = 6940 d ≈ 19 a       
   Millennium              ≡ 1000 years (1000 a)        = 31.556952 Gs^[note  
                                                        2]^[note 3]           
                           ≡                                                  
   Milliday         md     Link:                        = 86.4 s
                           mw-deduplicated-inline-style 
                           1⁄1000 d                     
   Minute           min    ≡ 60 s, due to leap seconds  = 60 s^[note 3]       
                           sometimes 59 s or 61 s,      
   Moment                  ≡ 90 s                       = 90 s                
   Month (full)     mo     ≡ 30 d^[26]                  = 2.592×10^6 s^[note  
                                                        3]                    
   Month (Greg.     mo     = 30.436875 d                ≈ 2.6297 Ms^[note 3]  
   av.)             
   Month (hollow)   mo     ≡ 29 d^[26]                  = 2.5056 Ms^[note 3]  
   Month (synodic)  mo     Cycle time of moon phases ≈  ≈ 2.551 Ms            
                           29.530589 d (average)        
                           = 48 mo (full) + 48 mo                             
   Octaeteris              (hollow) + 3 mo              = 252.4608 Ms^[note   
                           (full)^[27]^[28] = 8 a of    3]
                           365.25 d = 2922 d            
                           ≡ (                                                
                           Link:                                              
                           mw-deduplicated-inline-style ≈
   Planck time             Gℏ⁄c^5)^                     5.39116×10^−44 s^[29]
                           Link:                        
                           mw-deduplicated-inline-style 
                           1⁄2                          
                           ≡ Time of 9192631770 periods                       
                           of the radiation             
                           corresponding to the         
                           transition between the two   
                           hyperfine levels of the      
   Second (SI base         ground state of the          
   unit)            s      caesium-133 atom at 0 K^[12] (SI base unit)
                           (but other seconds are       
                           sometimes used in            
                           astronomy). Also that time   
                           it takes for light to travel 
                           a distance of 299792458      
                           metres.                      
   Shake                   ≡ 10^−8 s                    = 10 ns               
   Sigma                   ≡ 10^−6 s                    = 1 μs                
   Sothic cycle            ≡ 1461 a of 365 d            = 46.074096 Gs        
   Svedberg         S      ≡ 10^−13 s                   = 100 fs              
   Week             wk     ≡ 7 d = 168 h = 10080 min    = 604.8 ks^[note 3]   
   Year (common)    a, y,  365 d                        = 31.536 Ms^[note     
                    or yr                               3]^[30]               
                           = 365.2425 d average,                              
                           calculated from common years                       
   Year (Gregorian) a, y,  (365 d) plus leap years (366 = 31.556952 Ms^[note
                    or yr  d) on most years divisible   3]
                           by 4. See leap year for      
                           details.                     
                           = 365.25 d average,                                
   Year (Julian)    a, y,  calculated from common years = 31.5576 Ms
                    or yr  (365 d) plus one leap year   
                           (366 d) every four years     
   Year (leap)      a, y,  366 d                        = 31.6224 Ms^[note    
                    or yr                               3]^[30]               
                           Conceptually, the length of                        
                           time it takes for the Sun to 
   Year (mean       a, y,  return to the same position  
   tropical)        or yr  in the cycle of seasons,     ≈ 31.556925 Ms
                           ^[Converter 1] approximately 
                           365.24219 d, each day being  
                           86400 SI seconds^[31]        
                           ≡ Time taken for Sun to                            
                    a, y,  return to the same position  
   Year (sidereal)  or yr  with respect to the stars of ≈ 31.5581497632 Ms
                           the celestial sphere,        
                           approximately 365.256363 d   
   Notes:           
    1. ^ see Callippic cycle for explanation of the differences
    2. ^ ^a ^b ^c This is based on the average Gregorian year. See above for
       definition of year lengths.
    3. ^ ^a ^b ^c ^d ^e ^f ^g ^h ^i ^j ^k ^l ^m ^n ^o Where UTC is observed,
       the length of this unit may increase or decrease
       depending on the number of leap seconds which occur during the time
       interval in question.
    4. ^ The length of ancient lustral cycles was not constant; see Lustrum
       for more details

  Frequency[edit]

                                   Frequency
   Name of unit       Symbol Definition                  Relation to SI units 
   Actions per minute APM    ≡ 1/60 Hz                   ≈ 0.0167 Hz          
   Cycle per second   cps    ≡ 1 Hz                      = 1 cps = 1 Hz       
   degree per second  deg/s  ≡ 1 °/s ≡ 1/360 Hz          = 0.0027 Hz          
   hertz (SI unit)    Hz     ≡ One cycle per second      = 1 Hz = 1/s         
   Radian per second  rad/s  ≡ 1/(2π) Hz                 ≈ 0.159155 Hz        
                             ≡ One unit rpm equals one                        
   revolutions per    rpm    rotation completed around a ≈ 0.104719755 rad/s
   minute                    fixed axis in one minute of 
                             time.                       

  Speed or velocity[edit]

                                     Speed
   Name of unit     Symbol Definition                 Relation to SI units    
   foot per hour    fph    ≡ 1 ft/h                   = 8.46×10^−5 m/s        
   foot per minute  fpm    ≡ 1 ft/min                 = 5.08×10^−3 m/s        
   foot per second  fps    ≡ 1 ft/s                   = 3.048×10^−1 m/s       
   furlong per             ≡ furlong/fortnight        ≈ 1.663095×10^−4 m/s    
   fortnight        
   inch per hour    iph    ≡ 1 in/h                   = 7.05×10^−6 m/s        
   inch per minute  ipm    ≡ 1 in/min                 = 4.23×10^−4 m/s        
   inch per second  ips    ≡ 1 in/s                   = 2.54×10^−2 m/s        
   kilometre per    km/h   ≡ 1 km/h                   = 2.7×10^−1 m/s         
   hour             
   knot             kn     ≡ 1 nmi/h = 1.852 km/h     = 0.514 m/s             
   knot (Admiralty) kn     ≡ 1 NM (Adm)/h =           = 0.514773 m/s          
                           1.853184 km/h^[32]         
                           Ratio of the speed to the  ≈ 340 m/s in air at sea 
   mach number      M      speed of sound^[note 1] in level                   
                           the medium (unitless).     ≈ 295 m/s in air at jet 
                                                      altitudes               
   metre per second m/s    ≡ 1 m/s                    = 1 m/s                 
   (SI unit)        
   mile per hour    mph    ≡ 1 mi/h                   = 0.44704 m/s           
   mile per minute  mpm    ≡ 1 mi/min                 = 26.8224 m/s           
   mile per second  mps    ≡ 1 mi/s                   = 1609.344 m/s          
   speed of light   c      ≡ 299792458 m/s            = 299792458 m/s         
   in vacuum        
   speed of sound          1225 to 1062 km/h                                  
   in air           s      (761–660 mph or            ≈ 340 to 295 m/s
                           661–574 kn)^[note 1]       
   Note             
                    
   Link: mw-deduplicated-inline-style
    1. ^ ^a ^b The speed of sound varies especially with temperature and
       pressure from about 340 m/s (1,225 km/h or 761 mph or 661 kn)
       in air at sea level to about 300 m/s (1,062 km/h or 660 mph or 573 kn)
       at jet altitudes (12200 m or 40000 ft).^[33]

   A velocity consists of a speed combined with a direction; the speed part
   of the velocity takes units of speed.

  Flow (volume)[edit]

                                      Flow
   Name of unit        Symbol          Definition   Relation to SI units      
   cubic foot per      CFM^[citation   ≡ 1 ft^3/min = 4.719474432×10^−4 m^3/s 
   minute              needed]         
   cubic foot per      ft^3/s          ≡ 1 ft^3/s   = 0.028316846592 m^3/s    
   second              
   cubic inch per      in^3/min        ≡ 1 in^3/min = 2.7311773×10^−7 m^3/s   
   minute              
   cubic inch per      in^3/s          ≡ 1 in^3/s   = 1.6387064×10^−5 m^3/s   
   second              
   cubic metre per     m^3/s           ≡ 1 m^3/s    = 1 m^3/s                 
   second (SI unit)    
   gallon (US fluid)   GPD^[citation   ≡ 1 gal/d    = 4.381263638×10^−8 m^3/s 
   per day             needed]         
   gallon (US fluid)   GPH^[citation   ≡ 1 gal/h    = 1.051503273×10^−6 m^3/s 
   per hour            needed]         
   gallon (US fluid)   GPM^[citation   ≡ 1 gal/min  = 6.30901964×10^−5 m^3/s  
   per minute          needed]         
   litre per minute    l/min or L/min  ≡ 1 L/min    = 1.6×10^−5 m^3/s         

  Acceleration[edit]

                                  Acceleration
   Name of unit                  Symbol Definition      Relation to SI units  
   foot per hour per second      fph/s  ≡ 1 ft/(h⋅s)    = 8.46×10^−5 m/s^2    
   foot per minute per second    fpm/s  ≡ 1 ft/(min⋅s)  = 5.08×10^−3 m/s^2    
   foot per second squared       fps^2  ≡ 1 ft/s^2      = 3.048×10^−1 m/s^2   
   gal; galileo                  Gal    ≡ 1 cm/s^2      = 10^−2 m/s^2         
   inch per minute per second    ipm/s  ≡ 1 in/(min⋅s)  = 4.23×10^−4 m/s^2    
   inch per second squared       ips^2  ≡ 1 in/s^2      = 2.54×10^−2 m/s^2    
   knot per second               kn/s   ≡ 1 kn/s        ≈ 5.14×10^−1 m/s^2    
   metre per second squared      m/s^2  ≡ 1 m/s^2       = 1 m/s^2             
   (SI unit)                     
   mile per hour per second      mph/s  ≡ 1 mi/(h⋅s)    = 4.4704×10^−1 m/s^2  
   mile per minute per second    mpm/s  ≡ 1 mi/(min⋅s)  = 26.8224 m/s^2       
   mile per second squared       mps^2  ≡ 1 mi/s^2      = 1.609344×10^3 m/s^2 
   standard gravity              g_0    ≡ 9.80665 m/s^2 = 9.80665 m/s^2       

  Force[edit]

   Link: mw-deduplicated-inline-style
   See also: Weight § Mass, and Mass versus weight

                                     Force
Name of unit      Symbol        Definition                   Relation to SI units    
                                ≡                                                    
atomic unit of                  Link:                        ≈                       
force                           mw-deduplicated-inline-style 8.23872206×10^−8 N^[34]
                                m_e⋅α^2⋅c^2⁄a_0              
dyne (CGS unit)   dyn           ≡ g⋅cm/s^2                   = 10^−5 N               
kilogram-force;                                                                      
kilopond;         kgf; kp; gvf  ≡ g_0 × 1 kg                 = 9.80665 N
grave-force       
kip; kip-force    kip; kipf;    ≡ g_0 × 1000 lb              =                       
                  klbf                                       4.4482216152605×10^3 N  
milligrave-force, mgvf; gvtf    ≡ g_0 × 1 g                  = 9.80665 mN            
gravet-force      
long ton-force    tnf^[citation ≡ g_0 × 1 long ton           =                       
                  needed]                                    9.96401641818352×10^3 N 
                                A force capable of giving a                          
newton (SI unit)  N             mass of one kilogram an      = 1 N = 1 kg⋅m/s^2
                                acceleration of one metre    
                                per second per second.^[35]  
ounce-force       ozf           ≡ g_0 × 1 oz                 = 0.27801385095378125 N 
pound-force       lbf           ≡ g_0 × 1 lb                 = 4.4482216152605 N     
poundal           pdl           ≡ 1 lb⋅ft/s^2                = 0.138254954376 N      
short ton-force   tnf^[citation ≡ g_0 × 1 short ton          = 8.896443230521×10^3 N 
                  needed]       
sthene (mts unit) sn            ≡ 1 t⋅m/s^2                  = 10^3 N                

  Pressure or mechanical stress[edit]

                                    Pressure
   Name of unit   Symbol   Definition                   Relation to SI units    
   atmosphere     atm                                   ≡ 101325 Pa^[36]        
   (standard)     
   atmosphere     at       ≡ 1 kgf/cm^2                 = 9.80665×10^4 Pa^[36]  
   (technical)    
   bar            bar      ≡ 100000 Pa                  ≡ 10^5 Pa               
   barye                   ≡ 1 dyn/cm^2                 = 0.1 Pa                
   (CGS unit)     
   centimetre of  cmHg     ≡ 13595.1 kg/m^3 × 1 cm ×    ≈ 1.33322×10^3 Pa^[36]  
   mercury                 g_0                          
   centimetre of  cmH_2O   ≈ 999.972 kg/m^3 × 1 cm ×    ≈ 98.0638 Pa^[36]       
   water (4 °C)            g_0                          
   foot of                 ≡ 13595.1 kg/m^3 × 1 ft ×                            
   mercury        ftHg     g_0                          ≈ 4.063666×10^4 Pa^[36]
   (conventional) 
   foot of water  ftH_2O   ≈ 999.972 kg/m^3 × 1 ft ×    ≈ 2.98898×10^3 Pa^[36]  
   (39.2 °F)               g_0                          
   inch of                 ≡ 13595.1 kg/m^3 × 1 in ×                            
   mercury        inHg     g_0                          ≈ 3.386389×10^3 Pa^[36]
   (conventional) 
   inch of water  inH_2O   ≈ 999.972 kg/m^3 × 1 in ×    ≈ 249.082 Pa^[36]       
   (39.2 °F)               g_0                          
   kilogram-force                                                               
   per square     kgf/mm^2 ≡ 1 kgf/mm^2                 = 9.80665×10^6 Pa^[36]
   millimetre     
   kip per square ksi      ≡ 1 kipf/sq in               ≈ 6.894757×10^6 Pa^[36] 
   inch           
   long ton per            ≡ 1 long ton × g_0 / 1 sq ft ≈                       
   square foot                                          1.0725178011595×10^5 Pa 
   micrometre of  μmHg     ≡ 13595.1 kg/m^3 × 1 μm ×    ≈ 0.1333224 Pa^[36]     
   mercury                 g_0 ≈ 0.001 torr             
   millimetre of  mmHg     ≡ 13595.1 kg/m^3 × 1 mm ×    ≈ 133.3224 Pa^[36]      
   mercury                 g_0 ≈ 1 torr                 
   millimetre of           ≈ 999.972 kg/m^3 × 1 mm ×                            
   water          mmH_2O   g_0 = 0.999972 kgf/m^2       = 9.80638 Pa
   (3.98 °C)      
   pascal         Pa       ≡ N/m^2 = kg/(m⋅s^2)         = 1 Pa^[37]             
   (SI unit)      
   pièze (mts     pz       ≡ 1000 kg/m⋅s^2              = 10^3 Pa = 1 kPa       
   unit)          
   pound per      psf      ≡ 1 lbf/ft^2                 ≈ 47.88026 Pa^[36]      
   square foot    
   pound per      psi      ≡ 1 lbf/in^2                 ≈ 6.894757×10^3 Pa^[36] 
   square inch    
   poundal per    pdl/sq   ≡ 1 pdl/sq ft                ≈ 1.488164 Pa^[36]      
   square foot    ft       
   short ton per           ≡ 1 short ton × g_0 / 1 sq   ≈ 9.5760518×10^4 Pa     
   square foot             ft                           
                           ≡                                                    
   torr           torr     Link:                        ≈ 133.3224 Pa^[36]
                           mw-deduplicated-inline-style 
                           101325⁄760 Pa                

  Torque or moment of force[edit]

                                     Torque
   Name of unit         Symbol Definition        Relation to SI units         
   pound-force-foot     lbf⋅ft ≡ g_0 × 1 lb ×    = 1.3558179483314004 N⋅m     
                               1 ft              
   poundal-ft           pdl⋅ft ≡ 1 lb⋅ft^2/s^2   = 4.21401100938048×10^−2 N⋅m 
   pound force-inch     lbf⋅in ≡ g_0 × 1 lb × 1  = 0.1129848290276167 N⋅m     
                               in                
   kilogram force-meter kgf⋅m  ≡ g_0 × N × m     = 9.80665 N⋅m                
   Newton metre         N⋅m    ≡ N × m =         = 1 N⋅m                      
   (SI unit)                   kg⋅m^2/s^2        

  Energy[edit]

                                     Energy
Name of unit      Symbol      Definition                   Relation to SI units        
barrel of oil     boe         ≈ 5.8×10^6 BTU_59 °F         ≈ 6.12×10^9 J               
equivalent        
British thermal   BTU_ISO     ≡ 1.0545×10^3 J              = 1.0545×10^3 J             
unit (ISO)        
British thermal                                                                        
unit              BTU_IT                                   = 1.05505585262×10^3 J
(International    
Table)            
British thermal   BTU_mean                                 ≈ 1.05587×10^3 J            
unit (mean)       
British thermal                                                                        
unit              BTU_th                                   ≈ 1.054350×10^3 J
(thermochemical)  
British thermal   BTU_39 °F                                ≈ 1.05967×10^3 J            
unit (39 °F)      
British thermal   BTU_59 °F   ≡ 1.054804×10^3 J            = 1.054804×10^3 J           
unit (59 °F)      
British thermal   BTU_60 °F                                ≈ 1.05468×10^3 J            
unit (60 °F)      
British thermal   BTU_63 °F                                ≈ 1.0546×10^3 J             
unit (63 °F)      
calorie                                                                                
(International    cal_IT      ≡ 4.1868 J                   = 4.1868 J
Table)            
                              Link:                                                    
                              mw-deduplicated-inline-style 
calorie (mean)    cal_mean    1⁄100 of the energy required ≈ 4.19002 J
                              to warm one gram of air-free 
                              water from 0 °C to 100 °C at 
                              a pressure of 1 atm          
calorie           cal_th      ≡ 4.184 J                    = 4.184 J                   
(thermochemical)  
Calorie (US; FDA) Cal         ≡ 1 kcal = 1000 cal          = 4184 J                    
calorie (3.98 °C) cal_3.98 °C                              ≈ 4.2045 J                  
calorie (15 °C)   cal_15 °C   ≡ 4.1855 J                   = 4.1855 J                  
calorie (20 °C)   cal_20 °C                                ≈ 4.1819 J                  
Celsius heat unit                                                                      
(International    CHU_IT      ≡ 1 BTU_IT × 1 K/°R          = 1.899100534716×10^3 J
Table)            
cubic centimetre                                                                       
of atmosphere;    cc atm; scc ≡ 1 atm × 1 cm^3             = 0.101325 J
standard cubic    
centimetre        
cubic foot of                                                                          
atmosphere;       cu ft atm;  ≡ 1 atm × 1 ft^3             = 2.8692044809344×10^3 J
standard cubic    scf
foot              
cubic foot of                 ≡ 1000 BTU_IT                = 1.05505585262×10^6 J      
natural gas       
cubic yard of                                                                          
atmosphere;       cu yd atm;  ≡ 1 atm × 1 yd^3             = 77.4685209852288×10^3 J
standard cubic    scy
yard              
electronvolt      eV          ≡ e × 1 V                    ≡ 1.602176634×10^−19 J      
erg (CGS unit)    erg         ≡ 1 g⋅cm^2/s^2               = 10^−7 J                   
foot-pound force  ft lbf      ≡ g_0 × 1 lb × 1 ft          = 1.3558179483314004 J      
foot-poundal      ft pdl      ≡ 1 lb⋅ft^2/s^2              = 4.21401100938048×10^−2 J  
gallon-atmosphere imp gal atm ≡ 1 atm × 1 gal (imp)        = 460.63256925 J            
(imperial)        
gallon-atmosphere US gal atm  ≡ 1 atm × 1 gal (US)         = 383.5568490138 J          
(US)              
hartree, atomic   E_h         ≡ m_e⋅α^2⋅c^2 (= 2 Ry)       ≈ 4.359744×10^−18 J         
unit of energy    
horsepower-hour   hp⋅h        ≡ 1 hp × 1 h                 =                           
                                                           2.684519537696172792×10^6 J 
inch-pound force  in lbf      ≡ g_0 × 1 lb × 1 in          = 0.1129848290276167 J      
                              The work done when a force                               
                              of one newton moves the      = 1 J = 1 m⋅N =             
joule (SI unit)   J           point of its application a   1 kg⋅m^2/s^2 = 1 C⋅V =      
                              distance of one metre in the 1 W⋅s
                              direction of the force.^[35] 
kilocalorie;      kcal; Cal   ≡ 1000 cal_IT                = 4.1868×10^3 J             
large calorie     
kilowatt-hour;    kW⋅h;                                                                
Board of Trade    B.O.T.U.    ≡ 1 kW × 1 h                 = 3.6×10^6 J
Unit              
litre-atmosphere  l atm; sl   ≡ 1 atm × 1 L                = 101.325 J                 
quad                          ≡ 10^15 BTU_IT               = 1.05505585262×10^18 J     
rydberg           Ry          ≡ R_∞⋅ℎ⋅c                    ≈ 2.179872×10^−18 J         
therm (E.C.)                  ≡ 100000 BTU_IT              = 105.505585262×10^6 J      
therm (US)                    ≡ 100000 BTU_59 °F           = 105.4804×10^6 J           
thermie           th          ≡ 1 Mcal_IT                  = 4.1868×10^6 J             
tonne of coal     TCE         ≡ 7 Gcal_th                  = 29.288×10^9 J             
equivalent        
tonne of oil      toe         ≡ 10 Gcal_IT                 = 41.868×10^9 J             
equivalent        
ton of TNT        tTNT        ≡ 1 Gcal_th                  = 4.184×10^9 J              
watt hour         W⋅h         ≡ 1 W × 1 h                  = 3.6×10^3 J                
watt second       W⋅s         ≡ 1 J                        = 1×10^0 J                  

  Power or heat flow rate[edit]

                                     Power
   Name of unit     Symbol        Definition        Relation to SI units      
   atmosphere-cubic atm           ≡ 1 atm ×                                   
   centimetre per   ccm^[citation 1 cm^3/min        = 1.68875×10^−3 W
   minute           needed]       
   atmosphere-cubic atm           ≡ 1 atm ×                                   
   centimetre per   ccs^[citation 1 cm^3/s          = 0.101325 W
   second           needed]       
   atmosphere-cubic atm           ≡ 1 atm × 1 cu                              
   foot per hour    cfh^[citation ft/h              = 0.79700124704 W
                    needed]       
   atmosphere-cubic atm           ≡ 1 atm × 1 cu                              
   foot per minute  cfm^[citation ft/min            = 47.82007468224 W
                    needed]       
   atmosphere-cubic atm           ≡ 1 atm × 1 cu                              
   foot per second  cfs^[citation ft/s              = 2.8692044809344×10^3 W
                    needed]       
   BTU                                                                        
   (International   BTU_IT/h      ≡ 1 BTU_IT/h      ≈ 0.293071 W
   Table) per hour  
   BTU                                                                        
   (International   BTU_IT/min    ≡ 1 BTU_IT/min    ≈ 17.584264 W
   Table) per       
   minute           
   BTU                                                                        
   (International   BTU_IT/s      ≡ 1 BTU_IT/s      = 1.05505585262×10^3 W
   Table) per       
   second           
   calorie                                                                    
   (International   cal_IT/s      ≡ 1 cal_IT/s      = 4.1868 W
   Table) per       
   second           
   erg per second   erg/s         ≡ 1 erg/s         = 10^−7 W                 
   foot-pound-force ft⋅lbf/h      ≡ 1 ft lbf/h      ≈ 3.766161×10^−4 W        
   per hour         
   foot-pound-force ft⋅lbf/min    ≡ 1 ft lbf/min    =                         
   per minute                                       2.259696580552334×10^−2 W 
   foot-pound-force ft⋅lbf/s      ≡ 1 ft lbf/s      = 1.3558179483314004 W    
   per second       
   horsepower       hp            ≈ 34.5 lb/h ×     ≈ 9809.5 W^[38]           
   (boiler)                       970.3 BTU_IT/lb   
   horsepower                                                                 
   (European        hp            ≡ 75 kp⋅m/s       = 736 W^[citation needed]
   electrical)      
   horsepower       hp            ≡ 746 W           = 746 W^[38]              
   (electrical)     
   horsepower       hp            ≡                 = 745.69987158227022 W    
   (mechanical)                   550 ft⋅lbf/s^[38] 
   horsepower       hp or PS      ≡ 75 m⋅kgf/s      = 735.49875 W^[38]        
   (metric)         
   litre-atmosphere L·atm/min     ≡ 1 atm × 1 L/min = 1.68875 W               
   per minute       
   litre-atmosphere L·atm/s       ≡ 1 atm × 1 L/s   = 101.325 W               
   per second       
   lusec            lusec         ≡ 1 L·µmHg/s      ≈ 1.333×10^−4 W           
                                  ^[20]             
   poncelet         p             ≡ 100 m⋅kgf/s     = 980.665 W               
   square foot                                                                
   equivalent       sq ft EDR     ≡ 240 BTU_IT/h    ≈ 70.337057 W
   direct radiation 
   ton of air                     ≡ 2000 lb of ice  ≈ 3504 W                  
   conditioning                   melted / 24 h     
   ton of                         ≡ 2240 lb ×                                 
   refrigeration                  ice_IT / 24 h:    ≈ 3.938875×10^3 W
   (imperial)                     ice_IT = 144 °F × 
                                  2326 J/kg⋅°F      
   ton of                         ≡ 2000 lb ×                                 
   refrigeration                  ice_IT / 24 h:    ≈ 3.516853×10^3 W
   (IT)                           ice_IT = 144 °F × 
                                  2326 J/kg⋅°F      
                                  The power which                             
                                  in one second of  = 1 W = 1 J/s = 1 N⋅m/s = 
   watt (SI unit)   W             time gives rise   1 kg⋅m^2/s^3
                                  to one joule of   
                                  energy.^[35]      

  Action[edit]

                                     Action
   Name of Symbol Definition                      Relation to SI units        
   unit    
   atomic         ≡ ℏ ≡                                                       
   unit of au     Link:                           ≈                           
   action         mw-deduplicated-inline-style    1.05457168×10^−34 J⋅s^[39]
                  ℎ⁄2π                            

  Dynamic viscosity[edit]

                               Dynamic viscosity
   Name of unit          Symbol     Definition          Relation to SI units  
   pascal second         Pa⋅s       ≡ N⋅s/m^2, kg/(m⋅s) = 1 Pa⋅s              
   (SI unit)             
   poise (CGS unit)      P          ≡ 1 barye⋅s         = 0.1 Pa⋅s            
   pound per foot hour   lb/(ft⋅h)  ≡ 1 lb/(ft⋅h)       ≈ 4.133789×10^−4 Pa⋅s 
   pound per foot second lb/(ft⋅s)  ≡ 1 lb/(ft⋅s)       ≈ 1.488164 Pa⋅s       
   pound-force second    lbf⋅s/ft^2 ≡ 1 lbf⋅s/ft^2      ≈ 47.88026 Pa⋅s       
   per square foot       
   pound-force second    lbf⋅s/in^2 ≡ 1 lbf⋅s/in^2      ≈ 6894.757 Pa⋅s       
   per square inch       

  Kinematic viscosity[edit]

                              Kinematic viscosity
   Name of unit                      Symbol Definition Relation to SI units 
   square foot per second            ft^2/s ≡ 1 ft^2/s = 0.09290304 m^2/s   
   square metre per second (SI unit) m^2/s  ≡ 1 m^2/s  = 1 m^2/s            
   stokes (CGS unit)                 St     ≡ 1 cm^2/s = 10^−4 m^2/s        

  Electric current[edit]

                                Electric current
   Name of unit          Symbol Definition               Relation to SI units 
                                ≡ one coulomb of charge                       
   ampere (SI base unit) A      going past a given point (SI base unit)
                                per second.^[40]         
   electromagnetic unit; abamp  ≘ 10 A                   = 10 A               
   abampere (CGS unit)   
   esu per second;       esu/s  ≘ (10 A⋅cm/s) / c        ≈ 3.335641×10^−10 A  
   statampere (CGS unit) 

  Electric charge[edit]

                                Electric charge
   Name of unit       Symbol   Definition               Relation to SI units  
   abcoulomb;                                                                 
   electromagnetic    abC; emu ≘ 10 C                   = 10 C
   unit (CGS unit)    
   atomic unit of     au       ≡ e                      =                     
   charge                                               1.602176634×10^−19 C  
                               ≡ charge of exactly                            
   coulomb            C        1/(1.602176634×10^−19)   = 1 C = 1 A⋅s
                               elementary charges^[40]  
   faraday            F        ≡ 1 mol × N_A⋅e          ≈ 96485.3383 C        
   milliampere hour   mA⋅h     ≡ 0.001 A × 1 h          = 3.6 C               
   statcoulomb;                                                               
   franklin;          statC;   ≘ (10 A⋅cm) / c          ≈ 3.335641×10^−10 C
   electrostatic unit Fr; esu
   (CGS unit)         

  Electric dipole[edit]

                                Electric dipole
   Name of unit            Symbol Definition     Relation to SI units         
   atomic unit of electric ea_0                  ≈ 8.47835281×10^−30 C⋅m^[41] 
   dipole moment           
   coulomb-meter           C⋅m                   = 1 C⋅m                      
   debye                   D      ≡ 10^−10 esu⋅Å ≘ 3.33564095×10^−30 C⋅m^[42] 

  Electromotive force, electric potential difference[edit]

                          Voltage, electromotive force
   Name of unit      Symbol Definition                  Relation to SI units  
   abvolt (CGS unit) abV    ≘ 10^−8 V                   = 10^−8 V             
   statvolt          statV  ≘ c⋅(1 μJ/A⋅m)              = 299.792458 V        
   (CGS unit)        
                            The difference in electric                        
                            potential across two points                       
                            along a conducting wire     = 1 V = 1 W/A = 1     
   volt (SI unit)    V      carrying one ampere of      kg⋅m^2/(A⋅s^3) = 1
                            constant current when the   J/C
                            power dissipated between    
                            the points equals one       
                            watt.^[35]                  

  Electrical resistance[edit]

                             Electrical resistance
   Name of unit  Symbol Definition                      Relation to SI units  
                        The resistance between two                            
                        points in a conductor when one                        
   ohm (SI unit) Ω      volt of electric potential      = 1 Ω = 1 V/A = 1
                        difference, applied to these    kg⋅m^2/(A^2⋅s^3)
                        points, produces one ampere of  
                        current in the conductor.^[35]  

  Capacitance[edit]

                      Capacitor's ability to store charge
   Name of unit  Symbol Definition                      Relation to SI units  
                        The capacitance between two                           
   farad                parallel plates that results in = 1 F = 1 C/V = 1     
   (SI unit)     F      one volt of potential           A^2⋅s^4/(kg⋅m^2)
                        difference when charged by one  
                        coulomb of electricity.^[35]    

  Magnetic flux[edit]

                                 Magnetic flux
   Name of unit     Symbol Definition                    Relation to SI units 
   maxwell          Mx     ≘ 10^−8 Wb^[38]               = 10^−8 Wb           
   (CGS unit)       
                           Magnetic flux which, linking                       
                           a circuit of one turn, would                       
                           produce in it an              = 1 Wb = 1 V⋅s = 1
   weber (SI unit)  Wb     electromotive force of 1 volt kg⋅m^2/(A⋅s^2)
                           if it were reduced to zero at 
                           a uniform rate in 1           
                           second.^[35]                  

  Magnetic flux density[edit]

     What physicists call magnetic field is called magnetic flux density by
   electrical engineers and magnetic induction by applied mathematicians and
                             electrical engineers.
   Name of unit     Symbol Definition          Relation to SI units           
   gauss (CGS unit) G      ≡ Mx/cm^2 ≘ 10^−4 T = 10^−4 T ^[43]                
   tesla (SI unit)  T      ≡ Wb/m^2            = 1 T = 1 Wb/m^2 = 1           
                                               kg/(A⋅s^2)                     

  Inductance[edit]

                                   Inductance
   Name of unit    Symbol Definition                     Relation to SI units 
                          The inductance of a closed                          
                          circuit that produces one volt                      
   henry (SI unit) H      of electromotive force when    = 1 H = 1 Wb/A = 1
                          the current in the circuit     kg⋅m^2/(A⋅s)^2
                          varies at a uniform rate of    
                          one ampere per second.^[35]    

  Temperature[edit]

   Link: mw-deduplicated-inline-style
   Further information: Conversion of units of temperature

                                  Temperature
   Name of    Symbol Definition                   Relation to SI units         
   unit       
   degree     °C     [°C] ≡ [K] − 273.15          [K] ≡ [°C] + 273.15          
   Celsius    
                                                  [K] = 373.15 − [°De] ×       
   degree     °De                                 Link:                        
   Delisle                                        mw-deduplicated-inline-style 
                                                  2⁄3                          
                     [°F] ≡ [°C] ×                [K] ≡ ([°F] + 459.67) ×      
   degree     °F     Link:                        Link:                        
   Fahrenheit        mw-deduplicated-inline-style mw-deduplicated-inline-style 
                     9⁄5 + 32                     5⁄9                          
                                                  [K] = [°N] ×                 
   degree     °N                                  Link:                        
   Newton                                         mw-deduplicated-inline-style 
                                                  100⁄33 + 273.15              
                     [°R] ≡ [K] ×                                              
   degree     °R;    Link:                        [K] ≡ [°R] × 5/9
   Rankine           mw-deduplicated-inline-style 
                     9⁄5                          
                                                  [K] = [°Ré] ×                
   degree     °Ré                                 Link:                        
   Réaumur                                        mw-deduplicated-inline-style 
                                                  5⁄4 + 273.15                 
                                                  [K] = ([°Rø] − 7.5) ×        
   degree     °Rø                                 Link:                        
   Rømer                                          mw-deduplicated-inline-style 
                                                  40⁄21 + 273.15               
                                                  [K] ≡ [GM] ×                 
   Regulo Gas GM     [°F] ≡ [GM] × 25 + 250       Link:                        
   Mark                                           mw-deduplicated-inline-style 
                                                  125⁄9 + 394.26               
                     ≡ change in the                                           
   kelvin (SI        thermodynamic temperature T  
   base unit) K      that results in a change of  (SI base unit)
                     thermal energy kT by 1.380   
                     649 × 10^−23 J.^[44]         

  Information entropy[edit]

                              Information entropy
   Name of unit         Symbol    Definition     Relation to SI  Relation to  
                                                 units           bits         
   natural unit of                
   information; nit;    nat
   nepit                
   shannon              Sh        ≡ ln(2) × nat  ≈ 0.693147 nat  = 1 bit      
   hartley; ban         Hart; ban ≡ ln(10) × nat ≈ 2.302585 nat  
   bit                  bit; b                                   = 1 bit      
   nibble                         ≡ 4 bits                       = 2^2 bit    
   byte                 B         ≡ 8 bits                       = 2^3 bit    
   kilobyte (decimal)   kB        ≡ 1000 B                       = 8000 bit   
   kibibyte (kilobyte)  KiB; KB   ≡ 1024 B                       = 2^13 bit = 
                                                                 8192 bit     

   Modern standards (such as ISO 80000) prefer the shannon to the bit as a
   unit for a quantity of information entropy, whereas the (discrete) storage
   space of digital devices is measured in bits. Thus, uncompressed redundant
   data occupy more than one bit of storage per shannon of information
   entropy. The multiples of a bit listed above are usually used with this
   meaning.

  Luminous intensity[edit]

   The candela is the preferred nomenclature for the SI unit.

                               Luminous intensity
   Name of unit       Symbol Definition                           Relation to 
                                                                  SI units    
                             The luminous intensity, in a given               
                             direction, of a source that emits                
   candela (SI base   cd     monochromatic radiation of frequency (SI base
   unit)                     540×10^12 hertz and that has a       unit)
                             radiant intensity in that direction  
                             of 1/683 watt per steradian.^[40]    
                             ≡ cd The use of candlepower as a                 
   candlepower (new)  cp     unit is discouraged due to its       = 1 cd
                             ambiguity.                           
   candlepower (old,         Varies and is poorly                             
   pre-1948)          cp     reproducible.^[45] Approximately     ≈ 0.981 cd
                             0.981 cd.^[20]                       

  Luminance[edit]

                                   Luminance
   Name of unit                 Symbol  Definition      Relation to SI units  
   candela per square foot      cd/ft^2 ≡ cd/ft^2       ≈ 10.763910417 cd/m^2 
   candela per square inch      cd/in^2 ≡ cd/in^2       ≈ 1550.0031 cd/m^2    
   candela per square metre                                                   
   (SI unit); nit               cd/m^2  ≡ cd/m^2        = 1 cd/m^2
   (deprecated^[20])            
   footlambert                  fL      ≡ (1/π) cd/ft^2 ≈ 3.4262590996 cd/m^2 
   lambert                      L       ≡ (10^4/π)      ≈ 3183.0988618 cd/m^2 
                                        cd/m^2          
   stilb (CGS unit)             sb      ≡ 10^4 cd/m^2   = 10^4 cd/m^2         

  Luminous flux[edit]

                                 Luminous flux
   Name of unit    Symbol Definition                         Relation to SI   
                                                             units            
                          The luminous flux of a source that                  
                          emits monochromatic radiation of   
   lumen (SI unit) lm     frequency 540×10^12 hertz and that = 1 lm = 1 cd⋅sr
                          has a radiant flux of 1/683        
                          watt.^[40]                         

  Illuminance[edit]

                                  Illuminance
   Name of unit                      Symbol  Definition Relation to SI units 
   footcandle; lumen per square foot fc      ≡ lm/ft^2  = 10.763910417 lx    
   lumen per square inch             lm/in^2 ≡ lm/in^2  ≈ 1550.0031 lx       
   lux (SI unit)                     lx      ≡ lm/m^2   = 1 lx = 1 lm/m^2    
   phot (CGS unit)                   ph      ≡ lm/cm^2  = 10^4 lx            

  Radiation – source activity[edit]

                                 Radioactivity
   Name of unit   Symbol Definition                           Relation to SI  
                                                              units           
   becquerel      Bq     ≡ Number of disintegrations per      = 1 Bq = 1/s    
   (SI unit)             second                               
   curie          Ci     ≡ 3.7×10^10 Bq^[46]                  = 3.7×10^10 Bq  
   rutherford (H) Rd     ≡ 1 MBq                              = 10^6 Bq       

   Although becquerel (Bq) and hertz (Hz) both ultimately refer to the same
   SI base unit (s^−1), Hz is used only for periodic phenomena (i.e.
   repetitions at regular intervals), and Bq is only used for stochastic
   processes (i.e. at random intervals) associated with radioactivity.^[47]

  Radiation – exposure[edit]

                              Radiation – exposure
   Name of unit Symbol Definition                 Relation to SI units 
   roentgen     R      1 R ≡ 2.58×10^−4 C/kg^[38] = 2.58×10^−4 C/kg    

   The roentgen is not an SI unit and the NIST strongly discourages its
   continued use.^[48]

  Radiation – absorbed dose[edit]

                           Radiation – absorbed dose
   Name of unit   Symbol Definition     Relation to SI units        
   gray (SI unit) Gy     ≡ 1 J/kg^[49]  = 1 Gy = 1 J/kg = 1 m^2⋅s^2 
   rad            rad    ≡ 0.01 Gy^[38] = 0.01 Gy                   

  Radiation – equivalent dose[edit]

                          Radiation – equivalent dose
   Name of unit           Symbol Definition    Relation to SI units        
   Röntgen equivalent man rem    ≡ 0.01 Sv     = 0.01 Sv                   
   sievert (SI unit)      Sv     ≡ 1 J/kg^[47] = 1 Sv = 1 J/kg = 1 m^2⋅s^2 

   Although the definitions for sievert (Sv) and gray (Gy) would seem to
   indicate that they measure the same quantities, this is not the case. The
   effect of receiving a certain dose of radiation (given as Gy) is variable
   and depends on many factors, thus a new unit was needed to denote the
   biological effectiveness of that dose on the body; this is known as the
   equivalent dose and is shown in Sv. The general relationship between
   absorbed dose and equivalent dose can be represented as

           H = Q ⋅ D

   where H is the equivalent dose, D is the absorbed dose, and Q is a
   dimensionless quality factor. Thus, for any quantity of D measured in Gy,
   the numerical value for H measured in Sv may be different.^[50]

See also[edit]

     * Accuracy and precision
     * Conversion of units of temperature
     * English units
     * False precision
     * Imperial units
     * International System of Units
     * Mesures usuelles
     * Metric prefix (e.g. "kilo-" prefix)
     * Metric system
     * Natural units
     * Orders of Magnitude
     * Rounding
     * Significant figures
     * Unified Code for Units of Measure
     * United States customary units
     * Unit of length
     * Units (software)
     * Units conversion by factor-label
     * Units of measurement

Notes and references[edit]

   Link: mw-deduplicated-inline-style
    1. ^ Béla Bodó; Colin Jones (26 June 2013). Introduction to Soil
       Mechanics. John Wiley & Sons. pp. 9–. ISBN 978-1-118-55388-6.
    2. ^
       Link: mw-deduplicated-inline-style
       "Identity property of multiplication". Retrieved 2015-09-09.
    3. ^
       Link: mw-deduplicated-inline-style
       David V. Chadderton (2004). Building Services Engineering. Taylor &
       Francis. pp. 33–. ISBN 978-0-415-31535-7.
    4. ^
       Link: mw-deduplicated-inline-style
       Foot, C. J. (2005). Atomic physics. Oxford University Press.
       ISBN 978-0-19-850695-9.
    5. ^
       Link: mw-deduplicated-inline-style
       jobs (September 14, 2012). "The astronomical unit gets fixed : Nature
       News & Comment". Nature.com. doi:10.1038/nature.2012.11416.
       S2CID 123424704. Retrieved August 31, 2013. {{cite journal}}: Cite
       journal requires |journal= (help)
    6. ^ "NIST Reference on Constants, Units, and Uncertainty."(2010).
       National Institute of Standards and Technology. Retrieved October 17,
       2014.
    7. ^ ^a ^b ^c ^d ^e
       Link: mw-deduplicated-inline-style
       "NIST - National Institute of Standards and Technology". NIST.
    8. ^ ^a ^b ^c ^d ^e ^f ^g ^h ^i ^j ^k ^l ^m ^n Lide, D. (Ed.). (1990).
       Handbook of Chemistry and Physics (71st ed). Boca Raton, FL: CRC
       Press. Section 1.
    9. ^ ^a ^b National Bureau of Standards. (June 30, 1959). Refinement of
       values for the yard and the pound. Federal Register, viewed September
       20, 2006 at National Geodetic Survey web site.
   10. ^
       Link: mw-deduplicated-inline-style
       "International Astronomical Union - IAU". www.iau.org.
   11. ^ Klein, Herbert Arthur. (1988). The Science of Measurement: a
       Historical Survey. Mineola, NY: Dover Publications 0-4862-5839-4.
   12. ^ ^a ^b ^c
       Link: mw-deduplicated-inline-style
       The International System of Units, Section 2.1 (8 ed.), Bureau
       International des Poids et Mesures, 2006, archived from the original
       on October 1, 2009, retrieved August 26, 2009
   13. ^ International System of Units, Archived August 21, 2008, at the
       Wayback Machine 8th ed. (2006), Bureau International des Poids et
       Mesures, Section 4.1 Table 8.
   14. ^
       Link: mw-deduplicated-inline-style
       Cox, Arthur N., ed. (2000). Allen's Astrophysical Quantities
       (4th ed.). New York: AIP Press / Springer.
       Bibcode:2000asqu.book.....C. ISBN 0387987460.
   15. ^
       Link: mw-deduplicated-inline-style
       Binney, James; Tremaine, Scott (2008). Galactic Dynamics (2nd ed.).
       Princeton, NJ: Princeton University Press.
       Bibcode:2008gady.book.....B. ISBN 978-0-691-13026-2.
   16. ^ P. Kenneth Seidelmann, Ed. (1992). Explanatory Supplement to the
       Astronomical Almanac. Sausalito, CA: University Science Books. p. 716
       and s.v. parsec in Glossary.
   17. ^ ^a ^b ^c Whitelaw, Ian. (2007). A Measure of All Things: The Story
       of Man and Measurement. New York: Macmillan 0-312-37026-1. p. 152.
   18. ^ ^a ^b De Vinne, Theodore Low (1900). The practice of typography: a
       treatise on the processes of type-making, the point system, the names,
       sizes, styles and prices of plain printing types 2nd ed. New York: The
       Century Co. p. 142–150.
   19. ^ Pasko, Wesley Washington (1894). American dictionary of printing and
       bookmaking. (1894). New York: Howard Lockwood. p. 521.
   20. ^ ^a ^b ^c ^d ^e ^f ^g ^h ^i
       Link: mw-deduplicated-inline-style
       Rowlett, Russ (2005), How Many? A Dictionary of Units of Measurement
   21. ^ Thompson, A. and Taylor, B.N. (2008). Guide for the Use of the
       International System of Units (SI). National Institute of Standards
       and Technology Special Publication 811. p. 57.
   22. ^ ^a ^b ^c ^d ^e
       Link: mw-deduplicated-inline-style
       US Code of Federal Regulations, Title 21, Section 101.9, Paragraph
       (b)(5)(viii), archived from the original on August 13, 2009, retrieved
       August 29, 2009
   23. ^ Barry N. Taylor, Ed.,NIST Special Publication 330: The International
       System of Units (SI) (2001 Edition), Washington: US Government
       Printing Office, 43,"The 12th Conference Generale des Poids et Mesures
       (CGPM)...declares that the word "litre" may be employed as a special
       name for the cubic decimetre".
   24. ^ CODATA Value: atomic unit of mass. (2010). National Institute of
       Standards and Technology. Retrieved 29 May 2015.
   25. ^ The Swiss Federal Office for Metrology gives Zentner on a German
       language web page
       Link: mw-deduplicated-inline-style
       "Archived copy". Archived from the original on 2006-09-28. Retrieved
       2006-10-09.{{cite web}}: CS1 maint: archived copy as title (link) and
       quintal on the English translation of that page
       Link: mw-deduplicated-inline-style
       "Archived copy". Archived from the original on 2001-03-09. Retrieved
       2006-10-09.{{cite web}}: CS1 maint: archived copy as title (link); the
       unit is marked "spécifiquement suisse !"
   26. ^ ^a ^b Pedersen O. (1983). "Glossary" in Coyne, G., Hoskin, M., and
       Pedersen, O. Gregorian Reform of the Calendar: Proceedings of the
       Vatican Conference to Commemorate its 400th Anniversary. Vatican
       Observatory. Available from Astrophysics Data System.
   27. ^
       Link: mw-deduplicated-inline-style
       Richards, E.G. (1998), Mapping Time, Oxford University Press,
       pp. 94–95, ISBN 0-19-850413-6
   28. ^
       Link: mw-deduplicated-inline-style
       Steel, Duncan (2000), Marking Time, John Wiley & Sons, p. 46,
       ISBN 0-471-29827-1
   29. ^
       Link: mw-deduplicated-inline-style
       "CODATA Value: Planck time". physics.nist.gov. Retrieved 2018-06-20.
   30. ^ ^a ^b Richards, E. G. (2013). "Calendars" in S. E. Urban & P. K.
       Seidelmann, eds. Explanatory Supplement to the Astronomical Almanac.
       Mill Valley, CA: University Science Books.
   31. ^ Richards, E. G. (2013). "Calendars" in S. E. Urban & P. K.
       Seidelmann, eds. Explanatory Supplement to the Astronomical Almanac.
       Mill Valley, CA: University Science Books. p. 587.
   32. ^ Until 1970 the UK Admiralty (and until 1954 the US) used other
       definitions of the nautical mile and hence the knot. See also #Length
   33. ^ Tom Benson. (2010.) "Mach Number" Archived 2006-04-10 at the Wayback
       Machine in Beginner's Guide to Aeronautics. NASA.
   34. ^ CODATA Value: atomic unit of force. (2006). National Institute of
       Standards and Technology. Retrieved September 14, 2008.
   35. ^ ^a ^b ^c ^d ^e ^f ^g ^h
       Link: mw-deduplicated-inline-style
       Comité International des Poids et Mesures, Resolution 2, 1946,
       retrieved August 26, 2009
   36. ^ ^a ^b ^c ^d ^e ^f ^g ^h ^i ^j ^k ^l ^m ^n ^o ^p Barry N. Taylor,
       (April 1995), Guide for the Use of the International System of Units
       (SI) (NIST Special Publication 811), Washington, DC: US Government
       Printing Office, pp. 57–68.
   37. ^ Barry N. Taylor, (April 1995), Guide for the Use of the
       International System of Units (SI) (NIST Special Publication 811),
       Washington, DC: US Government Printing Office, p. 5.
   38. ^ ^a ^b ^c ^d ^e ^f ^g
       Link: mw-deduplicated-inline-style
       NIST Guide to SI Units, Appendix B.9, retrieved August 27, 2009
   39. ^ International System of Units, Archived July 16, 2012, at the
       Wayback Machine 8th ed. (2006), Bureau International des Poids et
       Mesures, Section 4.1 Table 7.
   40. ^ ^a ^b ^c ^d
       Link: mw-deduplicated-inline-style
       "SI brochure (2019)" (PDF). SI Brochure. BIPM. p. 132. Retrieved May
       23, 2019.
   41. ^
       Link: mw-deduplicated-inline-style
       The NIST Reference on Constants, Units, and Uncertainty, 2006,
       retrieved August 26, 2009
   42. ^ Robert G. Mortimer Physical chemistry,Academic Press, 2000
       Link: mw-deduplicated-inline-style
       ISBN 0-12-508345-9, page 677
   43. ^ Standard for the Use of the International System of Units (SI): The
       Modern Metric System IEEE/ASTM SI 10-1997. (1997). New York and West
       Conshohocken, PA: Institute of Electrical and Electronics Engineers
       and American Society for Testing and Materials. Tables A.1 through
       A.5.
   44. ^
       Link: mw-deduplicated-inline-style
       "Mise en pratique" (PDF). BIPM.
   45. ^
       Link: mw-deduplicated-inline-style
       The NIST Reference on Constants, Units, and Uncertainty, retrieved
       August 28, 2009
   46. ^ Ambler Thompson & Barry N. Taylor. (2008). Guide for the Use of the
       International System of Units (SI). Special Publication 811.
       Gaithersburg, MD: National Institute of Standards and Technology. p.
       10.
   47. ^ ^a ^b
       Link: mw-deduplicated-inline-style
       The International System of Units, Section 2.2.2., Table 3 (8 ed.),
       Bureau International des Poids et Mesures, 2006, archived from the
       original on June 18, 2007, retrieved August 27, 2009
   48. ^
       Link: mw-deduplicated-inline-style
       The NIST Guide to the SI (Special Publication 811), section 5.2, 2008,
       retrieved August 27, 2009
   49. ^ Ambler Thompson & Barry N. Taylor. (2008). Guide for the Use of the
       International System of Units (SI). Special Publication 811.
       Gaithersburg, MD: National Institute of Standards and Technology. p.
       5.
   50. ^
       Link: mw-deduplicated-inline-style
       Comité international des poids et mesures, 2002, Recommendation 2,
       retrieved August 27, 2009

   Notes

   Link: mw-deduplicated-inline-style
    1. ^ The technical definition of tropical year is the period of time for
       the ecliptic longitude of the Sun to increase 360 degrees. (Urban &
       Seidelmann 2013, Glossary, s.v. year, tropical)

External links[edit]

    Wikibooks has a book on the topic of: FHSST Physics Units:How to Change   
    Units                                                                     

    Wikivoyage has a travel guide for Metric and Imperial equivalents. 

     * Statutory Instrument 1995 No. 1804 Units of measurement regulations
       1995 From legislation.gov.uk
     * Link: mw-deduplicated-inline-style
       "NIST: Fundamental physical constants — Non-SI units" (PDF). Archived
       from the original (PDF) on 2016-12-27. Retrieved 2004-03-15. (35.7 KB)
     * NIST Guide to SI Units Many conversion factors listed.
     * The Unified Code for Units of Measure
     * Units, Symbols, and Conversions XML Dictionary
     * Units of Measurement Software at Curlie
     * Units of Measurement Online Conversion at Curlie
     * (in French)"Instruction sur les poids et mesures républicaines:
       déduites de la grandeur de la terre,
       uniformes pour toute la République,
       et sur les calculs relatifs à leur division décimale"

     * v         
     * t         
     * e         
   Systems of measurement
                            * International System of Units (SI)   
                 General    * UK imperial system                   
                            * US customary units                   
                            * Apothecaries'                        
                            * Avoirdupois                          
                 Specific   * Troy                                 
                            * Astronomical                         
   Current                  * Electrical                           
                            * English Engineering Units (US)       
                            * Hartree atomic                       
                            * Geometrised                          
                 Natural    * Lorentz–Heaviside                    
                            * Planck                               
                            * Quantum chromodynamical              
                            * Stoney                               
                          * Overview                               
                 Metric   * Outline                                
                          * History                                
   Background             * Metrication                            
                          * Overview                               
                 UK/US    * Comparison                             
                          * Foot–pound–second (FPS)                
                                 * metre–kilogram–second (MKS)     
                 Metric          * metre–tonne–second (MTS)        
                                 * centimetre–gram–second (CGS)    
                                 * gravitational                   
                                 * Byzantine                       
                                 * Cornish                         
                                 * Cypriot                         
                                 * Czech                           
                                 * Danish                          
                                 * Dutch                           
                                 * English                         
                                      * Winchester                 
                                      * Exchequer                  
                                 * Estonian                        
                                 * Finnish                         
                                 * French                          
                                      * Traditional                
                                      * Mesures usuelles           
                                 * German                          
                                 * Greek                           
                                 * Hungarian                       
                 Europe          * Icelandic                       
                                 * Irish                           
                                 * Italian                         
                                 * Latvian                         
                                 * Luxembourgian                   
                                 * Maltese                         
                                 * Norwegian                       
                                 * Ottoman                         
                                 * Polish                          
                                 * Portuguese                      
                                 * Romanian                        
                                 * Russian                         
                                 * Scottish                        
                                 * Serbian                         
                                 * Slovak                          
                                 * Spanish                         
                                 * Swedish                         
                                 * Swiss                           
                                 * Welsh                           
                                 * Afghan                          
                                 * Cambodian                       
                                 * Chinese                         
                                 * Hong Kong                       
                                 * Indian                          
   Historic                      * Indonesian                      
                                 * Japanese                        
                                 * Korean                          
                                 * Mongolian                       
                                 * Myanmar                         
                 Asia            * Nepalese                        
                                 * Omani                           
                                 * Philippine                      
                                 * Pegu                            
                                 * Singaporean                     
                                 * Sri Lankan                      
                                 * Syrian                          
                                 * Taiwanese                       
                                 * Tatar                           
                                 * Thai                            
                                 * Vietnamese                      
                                 * Algerian                        
                                 * Ethiopian                       
                                 * Egyptian                        
                                 * Eritrean                        
                                 * Guinean                         
                                 * Libyan                          
                 Africa          * Malagasy                        
                                 * Mauritian                       
                                 * Moroccan                        
                                 * Seychellois                     
                                 * Somali                          
                                 * South African                   
                                 * Tunisian                        
                                 * Tanzanian                       
                                 * Costa Rican                     
                                 * Cuban                           
                                 * Haitian                         
                 North America   * Honduran                        
                                 * Mexican                         
                                 * Nicaraguan                      
                                 * Puerto Rican                    
                                 * Argentine                       
                                 * Bolivian                        
                                 * Brazilian                       
                                 * Chilean                         
                 South America   * Colombian                       
                                 * Paraguayan                      
                                 * Peruvian                        
                                 * Uruguayan                       
                                 * Venezuelan                      
                   * Arabic                                        
                   * Biblical and Talmudic                         
                   * Egyptian                                      
                   * Greek                                         
   Ancient         * Hindu                                         
                   * Indian                                        
                   * Mesopotamian                                  
                   * Persian                                       
                   * Roman                                         
                   * Humorous                                      
   List articles   * Obsolete                                      
                   * Unusual                                       
                   * Absolute scale                                
   Other           * N-body                                        
                   * Modulor                                       

   Link: mw-deduplicated-inline-style

   Link: mw-deduplicated-inline-style
     * v                
     * t                
     * e                
   SI units             
                          * ampere                                 
                          * candela                    
                          * kelvin                     
   Base units             * kilogram                   
                          * metre                      
                          * mole                       
                          * second                     
                          * becquerel                  
                          * coulomb                    
                          * degree Celsius             
                          * farad                      
                          * gray                       
                          * henry                      
                          * hertz                      
                          * joule                      
                          * katal                      
                          * lumen                      
   Derived units          * lux                        
   with special names     * newton                     
                          * ohm                        
                          * pascal                     
                          * radian                     
                          * siemens                    
                          * sievert                    The SI logo
                          * steradian                  
                          * tesla                      
                          * volt                       
                          * watt                       
                          * weber                      
                          * astronomical unit          
                          * dalton                     
                          * day                        
                          * decibel                    
                          * degree of arc              
                          * electronvolt               
   Other accepted units   * hectare                    
                          * hour                       
                          * litre                      
                          * minute                     
                          * minute and second of arc   
                          * neper                      
                          * tonne                      
                          * Conversion of units        
                          * Metric prefixes            
   See also               * 2005–2019 definition       
                          * 2019 redefinition          
                          * Systems of measurement     
     * Category         

   Retrieved from
   "https://en.wikipedia.org/w/index.php?title=Conversion_of_units&oldid=1076138569"
   Categories:
     * Units of measurement
     * Metrication
     * Conversion of units of measurement
   Hidden categories:
     * CS1 errors: missing periodical
     * Webarchive template wayback links
     * CS1 maint: archived copy as title
     * Articles with short description
     * Short description matches Wikidata
     * Wikipedia articles needing clarification from December 2017
     * Articles needing additional references from January 2011
     * All articles needing additional references
     * All articles with unsourced statements
     * Articles with unsourced statements from August 2011
     * Articles with unsourced statements from May 2015
     * Articles with unsourced statements from November 2015
     * Articles with Curlie links
     * Articles with French-language sources (fr)

Navigation menu

   Personal tools
     * Not logged in
     * Talk
     * Contributions
     * Create account
     * Log in
   Namespaces
     * Article
     * Talk
   [ ] English
   Views
     * Read
     * Edit
     * View history
   [ ] More

  Search

   _____________________ [ Search ] [ Go ]
   Visit the main page
   Navigation
     * Main page
     * Contents
     * Current events
     * Random article
     * About Wikipedia
     * Contact us
     * Donate
   Contribute
     * Help
     * Learn to edit
     * Community portal
     * Recent changes
     * Upload file
   Tools
     * What links here
     * Related changes
     * Upload file
     * Special pages
     * Permanent link
     * Page information
     * Cite this page
     * Wikidata item
   Print/export
     * Download as PDF
     * Printable version
   In other projects
     * Wikimedia Commons
     * Wikivoyage
   Languages
     * العربية
     * বাংলা
     * Bân-lâm-gú
     * Bosanski
     * Català
     * Чӑвашла
     * Deutsch
     * Español
     * فارسی
     * Føroyskt
     * Français
     * 한국어
     * Հայերեն
     * Hrvatski
     * Bahasa Indonesia
     * Interlingua
     * Italiano
     * Magyar
     * Nederlands
     * 日本語
     * پنجابی
     * Polski
     * Português
     * Русский
     * Simple English
     * Slovenščina
     * Српски / srpski
     * Srpskohrvatski / српскохрватски
     * தமிழ்
     * తెలుగు
     * Українська
     * اردو
     * 粵語
     * 中文
   Edit links
     * This page was last edited on 9 March 2022, at 15:28 (UTC).
     * Text is available under the Creative Commons Attribution-ShareAlike
       License 3.0; additional terms may apply. By using this site, you agree
       to the Terms of Use and Privacy Policy. Wikipedia® is a registered
       trademark of the Wikimedia Foundation, Inc., a non-profit
       organization.
     * Privacy policy
     * About Wikipedia
     * Disclaimers
     * Contact Wikipedia
     * Mobile view
     * Developers
     * Statistics
     * Cookie statement
     * Wikimedia Foundation
     * Powered by MediaWiki
