Derived Units

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The seven SI base units are used to form all other units of measurement used in science and technology. These are called SI derived units and are listed in the table below. Note that the full names of SI units are always written in lower-case letters, but that unit symbols named after people usually have the first or only letter in upper-case. Derived units with worked examples found in this series of pages are shown in blue links.

becquerel Bq radioactivity (decays per units time) 1/s s -1 coulomb C electric charge or quantity of electricity s•A s•A degree Celsius °C temperature relative to 273.15 K K farad F electric capacitance C/V kg −1 •m −2 •s 4 •A 2 gray Gy absorbed dose of ionizing radiation J/kg m 2 •s −2 henry H inductance V•s/A = Wb/A kg•m 2 •s −2 •A −2 hertz Hz frequency 1/s s -1 joule J energy, work, heat N•m = C•V = W•s kg•m 2 •s −2 katal kat catalytic activity mol/s s -1 •mol lumen lm luminous flux cd•sr cd lux lx illuminance lm/m 2 m -2 •cd newton N force, weight kg•m/s 2 kg•m•s −2 ohm Ω electric resistance, impedance, reactance V/A kg•m 2 •s −3 •A −2 pascal Pa pressure, stress N/m 2 kg•m −1 •s −2 radian rad angle m/m dimensionless siemens S electrical conductance 1/Ω = A/V kg −1 •m −2 •s 3 •A 2 sievert Sv equivalent dose of ionizing radiation J/kg m 2 •s −2 steradian sr solid angle m 2 /m 2 dimensionless tesla T magnetic field strength, V•s/m 2 magnetic flux density = Wb/m 2 kg·s −2 •A −1 = N/(A•m) volt V voltage, electrical potential difference, W/A = J/C kg•m 2 •s −3 •A −1 electromotive force watt W power, radiant flux J/s = V•A kg•m 2 •s −3 weber Wb magnetic flux J/A kg•m 2 •s −2 •A −1

Expression Expression Name Symbol Quantity in terms of in terms of SI other units base units

Some other units are not derived SI units but commonly accepted, such as the litre (American English: liter).

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Derived Units

Go to the SI Units Explained Page

The seven SI base units are used to form all other units of measurement used in science and technology. These are called SI derived units and are listed in the table below. Note that the full names of SI units are always written in lower- case letters, but that unit symbols named after people usually have the first or only letter in upper-case. Derived units with worked examples found in this series of pages are shown in blue links.

becquerel Bq radioactivity (decays per units time) 1/s s -1 coulomb C electric charge or quantity of electricity s•A s•A degree Celsius °C temperature relative to 273.15 K K farad F electric capacitance C/V kg −1 •m −2 •s 4 •A 2 gray Gy absorbed dose of ionizing radiation J/kg m 2 •s −2 henry H inductance V•s/A = Wb/A kg•m 2 •s −2 •A −2 hertz Hz frequency 1/s s -1 joule J energy, work, heat N•m = C•V = W•s kg•m 2 •s −2 katal kat catalytic activity mol/s s -1 •mol lumen lm luminous flux cd•sr cd lux lx illuminance lm/m 2 m -2 •cd newton N force, weight kg•m/s 2 kg•m•s −2 ohm Ω electric resistance, impedance, reactance V/A kg•m 2 •s −3 •A −2 pascal Pa pressure, stress N/m 2 kg•m −1 •s −2 radian rad angle m/m dimensionless siemens S electrical conductance 1/Ω = A/V kg −1 •m −2 •s 3 •A 2 sievert Sv equivalent dose of ionizing radiation J/kg m 2 •s −2 steradian sr solid angle m 2 /m 2 dimensionless tesla T magnetic field strength/flux density V•s/m 2 = Wb/m 2 = N/(A•m) kg·s −2 •A −1 volt V voltage, potential diff, electromotive force W/A = J/C kg•m 2 •s −3 •A −1 watt W power, radiant flux J/s = V•A kg•m 2 •s −3 weber Wb magnetic flux J/A kg•m 2 •s −2 •A −1

Some other units are not derived SI units but commonly accepted, such as the litre (American English: liter).

The derived units shown below are given by name, symbol and quantity, as well as in terms of other units (in dark red) and then in terms of SI base units (in dark blue).