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SI brochure, Table 3 ( Section 2.2.2)

Table 3. Coherent derived units in the SI with special names and symbols

Derived quantity 
SI coherent derived unit ^{(a)} 

Name 
Symbol 
Expressed in terms of other SI units 
Expressed in terms of SI base units 

plane angle 
radian ^{(b)} 
rad 
1 ^{(b)} 
m/m 
solid angle 
steradian ^{(b)} 
sr ^{(c)} 
1 ^{(b)} 
m^{2}/m^{2} 
frequency 
hertz ^{(d)} 
Hz 

s^{–1} 
force 
newton 
N 

kg m s^{–2} 
pressure, stress 
pascal 
Pa 
N/m^{2} 
kg m^{–1} s^{–2} 
energy, work, amount of heat 
joule 
J 
N m 
kg m^{2} s^{–2} 
power, radiant flux 
watt 
W 
J/s 
kg m^{2} s^{–3} 
electric charge, amount of electricity 
coulomb 
C 

A s 
electric potential difference, electromotive force 
volt 
V 
W/A 
kg m^{2} s^{–3} A^{–1} 
capacitance 
farad 
F 
C/V 
kg^{–1} m^{–2} s^{4} A^{2} 
electric resistance 
ohm 

V/A 
kg m^{2} s^{–3} A^{–2} 
electric conductance 
siemens 
S 
A/V 
kg^{–1} m^{–2} s^{3} A^{2} 
magnetic flux 
weber 
Wb 
V s 
kg m^{2} s^{–2} A^{–1} 
magnetic flux density 
tesla 
T 
Wb/m^{2} 
kg s^{–2} A^{–1} 
inductance 
henry 
H 
Wb/A 
kg m^{2} s^{–2} A^{–2} 
Celsius temperature 
degree Celsius ^{(e)} 
°C 

K 
luminous flux 
lumen 
lm 
cd sr ^{(c)} 
cd sr 
illuminance 
lux 
lx 
lm/m^{2} 
cd sr m^{–2} 
activity referred to a radionuclide ^{(f)} 
becquerel ^{(d)} 
Bq 

s^{–1} 
absorbed dose, specific energy (imparted), kerma 
gray 
Gy 
J/kg 
m^{2} s^{–2} 
dose equivalent, ambient dose equivalent, directional dose equivalent, personal dose equivalent 
sievert ^{(g)} 
Sv 
J/kg 
m^{2} s^{–2} 
catalytic activity 
katal 
kat 

mol s^{–1} 
(a) 
The SI prefixes may be used with any of the special names and symbols, but when this is done the resulting unit will no longer be coherent. 
(b) 
The radian and steradian are special names for the number one that may be used to convey information about the quantity concerned. In practice the symbols rad and sr are used where appropriate, but the symbol for the derived unit one is generally omitted in specifying the values of dimensionless quantities. 
(c) 
In photometry the name steradian and the symbol sr are usually retained in expressions for units. 
(d) 
The hertz is used only for periodic phenomena, and the becquerel is used only for stochastic processes in activity referred to a radionuclide. 
(e) 
The degree Celsius is the special name for the kelvin used to express Celsius temperatures. The degree Celsius and the kelvin are equal in size, so that the numerical value of a temperature difference or temperature interval is the same when expressed in either degrees Celsius or in kelvins. 
(f) 
Activity referred to a radionuclide is sometimes incorrectly called radioactivity. 
(g) 
See CIPM Recommendation 2 (CI2002) on the use of the sievert. 








