This list of international units is subsidiary to the list of units article and lists widely used modern units in a form of sortable table.
Unit system Domain Derivation Unit name Unit symbol Dimension symbol Quantity name Definition In SI base units In other SI units SI Physics Basic secondWithin the context of the SI, the second is the coherent base unit of time, and is used in the definitions of derived units. The name "second" historically arose as being the 2nd-level sexagesimal division () of some quantity, the hour in this case, which the SI classifies as an "accepted" unit along with its first-level sexagesimal division the minute. s T time The duration of periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. s SI Physics Basic metre m L length The distance travelled by light in vacuum in second. m SI Physics Basic kilogramDespite the prefix "kilo-", the kilogram is the coherent base unit of mass, and is used in the definitions of derived units. Nonetheless, prefixes for the unit of mass are determined as if the gram were the base unit. kg M mass The kilogram is defined by setting the Planck constant exactly to (), given the definitions of the metre and the second. kg SI Physics Basic ampere A I electric current The flow of exactly times the elementary charge per second. Equalling approximately elementary charges per second. A SI Physics Basic kelvin K Θ thermodynamictemperature The kelvin is defined by setting the fixed numerical value of the Boltzmann constant to , (J = kg⋅m2⋅s−2), given the definition of the kilogram, the metre, and the second. K SI Physics Basic mole mol N amount ofsubstance The amount of substance of exactly elementary entities.When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles. This number is the fixed numerical value of the Avogadro constant, A, when expressed in the unit mol−1. mol SI Physics Basic candela cd J luminousintensity The luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency hertz and that has a radiant intensity in that direction of watt per steradian. cd SI Physics Relational radianThe radian and steradian are defined as dimensionless derived units. rad plane angle m/m 1 SI Physics Relational steradian sr solid angle m2/m2 1 SI Physics Relational hertz Hz frequency s−1 SI Physics Relational newton N force kg⋅m⋅s−2 SI Physics Relational pascal Pa pressure kg⋅m−1⋅s−2 N/m2 SI Physics Relational joule J energy, work, heat kg⋅m2⋅s−2 N⋅m = Pa⋅m3 SI Physics Relational watt W power, radiant flux kg⋅m2⋅s−3 J/s SI Physics Relational coulomb C electric charge s⋅A SI Physics Relational volt V electrical potential difference (voltage), emf kg⋅m2⋅s−3⋅A−1 W/A = J/C SI Physics Relational farad F capacitance kg−1⋅m−2⋅s4⋅A2 C/V SI Physics Relational ohm Ω resistance, impedance, reactance kg⋅m2⋅s−3⋅A−2 V/A SI Physics Relational siemens S electrical conductance kg−1⋅m−2⋅s3⋅A2 Ω−1 SI Physics Relational weber Wb magnetic flux kg⋅m2⋅s−2⋅A−1 V⋅s SI Physics Relational tesla T magnetic flux density kg⋅s−2⋅A−1 Wb/m2 SI Physics Relational henry H inductance kg⋅m2⋅s−2⋅A−2 Wb/A SI Physics Relational degree Celsius °C temperature relative to 273.15 K K SI Physics Relational lumen lm luminous flux cd⋅sr SI Physics Relational lux lx illuminance cd⋅sr⋅m−2 lm/m2 SI Physics Relational becquerel Bq radioactivity (decays per unit time) s−1 SI Physics Relational gray Gy absorbed dose (of ionising radiation) m2⋅s−2 J/kg SI Physics Relational sievert Sv equivalent dose (of ionising radiation) m2⋅s−2 J/kg SI Physics Relational katal kat catalytic activity mol⋅s−1 SI Physics Dimensional square metre m2 area SI Physics Dimensional cubic metre m3 volume SI Physics Relational metre per second m/s speed, velocity SI Physics Relational metre per second squared m/s2 acceleration SI Physics Relational reciprocal metre m−1 , or in optics , 1/ wavenumber, vergence (optics) SI Physics Relational kilogram per cubic metre kg/m3 density SI Physics Relational kilogram per square metre kg/m2 A surface density SI Physics Relational cubic metre per kilogram m3/kg specific volume SI Physics Relational ampere per square metre A/m2 current density SI Physics Relational ampere per metre A/m magnetic field strength SI Physics Relational mole per cubic metre mol/m3 concentration SI Physics Relational kilogram per cubic metre kg/m3 , mass concentration SI Physics Relational candela per square metre cd/m2 v luminance ? Economics Relational velocity of money ? Economics Relational gross margin
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