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  SI Derived Units  

SI derived unit

Name in terms of other units... Expression in terms of SI base units
plane angle radian (a) rad   m.m-1 = 1 (b)
solid angle steradian (a) sr (c)   m2.m-2 = 1 (b)
frequency hertz Hz   s-1
force newton N   m.kg.s-2
pressure, stress pascal Pa N/m2 m-1.kg.s-2
energy, work, quantity of heat joule J N.m m2.kg.s-2
power, radiant flux watt W J/s m2.kg.s-3
electric charge, quantity of electricity coulomb C   s.A
electric potential difference, electromotive force volt V W/A m2.kg.s-3.A-1
capacitance farad F C/V m-2.kg-1.s4.A2
electric resistance ohm W  V/A m2.kg.s-3.A-2
electric conductance siemens S A/V m-2.kg-1.s3.A2
magnetic flux weber Wb V.s m2.kg.s-2.A-1
magnetic flux density tesla T Wb/m2 kg.s-2.A-1
inductance henry H Wb/A m2. kg.s-2.A-2
Celsius temperature degree Celsius(d) C   K
luminous flux lumen lm cd.sr (c) m2.m-2.cd = cd
illuminance lux lx lm/m2 m2.m-4.cd = m-2.cd
activity (referred to a radionuclide) becquerel Bq   s-1
absorbed dose, specific energy (imparted), kerma gray Gy J/kg m2.s-2
dose equivalent, ambient dose equivalent, directional dose equivalent, personal dose equivalent, organ equivalent dose sievert Sv J/kg m2.s-2

(a) The radian and steradian may be used with advantage in expressions for derived units to distinguish between
     quantities of different nature but the same dimension.

(b) In practice, the symbols rad and sr are used where appropriate, but the derived unit "1" is generally omitted.

(c) In photometry, the name steradian and the symbol sr are usually retained in expressions for units.

(d) This unit may be used in combination with SI prefixes, e.g. millidegree Celsius, mC.

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