SI coherent derived units with special names and symbols

SI coherent derived units with special names and symbols

Coherent derived units are products of powers of base units that include no numerical factor other than 1. The base units and coherent derived units of the SI form a coherent set, designated the set of coherent SI units.

To simplify their expression, 22 coherent derived units in the SI have been given special names.

Name Symbol Quantity Expressed in terms of SI base units Expressed in terms of other SI units
hertz Hz frequency s-1 1/s
radian rad angle m/m
steradian sr solid angle m2/m2
newton N force kg m s‑2
pascal Pa pressure, stress kg m‑1 s‑2 N/m2
joule J energy, work, heat kg m2 s‑2 N m
W s
watt W power, radiant flux kg m2 s‑3 J/s
coulomb C electric charge s A F V
volt V electric
potential difference,
electromotive force
kg m2 s‑3 A‑1 W/A
farad F electric capacitance kg‑1 m‑2 s4 A2 C/V
ohm Ω electric resistance,
impedance, reactance
kg m2 s‑3 A‑2 1/S
siemens S electric conductance kg‑1 m‑2 s3 A2 1/Ω
weber Wb magnetic flux kg m2 s‑2 A‑1 V s
tesla T magnetic flux density,
magnetic field strength
kg s‑2 A‑1 Wb/m2
henry H inductance kg m2 s‑2 A‑2 Wb/A
degree Celsius °C Celsius temperature K
lumen lm luminous flux cd cd sr
lux lx illuminance m-2 cd lm/m2
becquerel Bq activity referred
to a radionuclide
s-1 1/s
gray Gy absorbed dose
(of ionising radiation)
m2 s-2 J/kg
sievert Sv dose equivalent
(of ionising radiation)
m2 s‑2 J/kg
katal kat catalytic activity s-1 mol