National Physical Laboratory

SI Derived Units

Derived units are units which may be expressed in terms of base units by means of mathematical symbols of multiplication and division.

Certain derived units have been given special names and symbols, and these special names and symbols may themselves be used in combination with the SI and other derived units to express the units of other quantities.

Learn more about measurement units and how to use them with NPL e-Learning

Examples of SI derived units expressed in terms of base units
Derived Quantity SI derived unit
  Name Symbol
area square metre m2
volume cubic metre m3
speed, velocity metre per second m/s
acceleration metre per second squared m/s2
wavenumber 1 per metre m-1
density, mass density kilogram per cubic metre kg/m3
specific volume cubic metre per kilogram m3/kg
current density ampere per square metre A/m2
magnetic field strength ampere per metre A/m
concentration
(of amount of substance)
mole per cubic metre mol/m3
luminance candela per square metre cd/m2
refractive index (the number) one 1(a)
(a) The symbol '1' is generally omitted in combination with a numerical value.

 

Learn more about measurement units and how to use them with NPL e-Learning

Registration

Please note that the information will not be divulged to third parties, or used without your permission

Login