SI Units
The international system of units known as the SI units is based on the seven basic units: Mass, Length, Time, Electric current, Temperature, Amount of substance and Luminous intensity.
- Basic Units
- The basic seven quantities from which other units are derived are tabulated below:
| Basic quantity | Name | Symbol |
| Mass | kilogram | kg |
| Length | metre | m |
| Time | second | s |
| Electric current | Ampere | A |
| Temperature | Kelvin | K |
| Amount of substance | mole | mol |
| Luminous intensity | candela | cd |
The radian and steradian may also be treated as basic units.
- Derived Units
- These are multiplications and divisions of the basic units to form derived units. Some of these derived units are listed below along with their derivation in terms of basic units:
| Derived quantity | Name | Symbol | Basic Unit Derivation |
| Capacitance | farad | F | kg-1m-2s4A2 |
| Charge | coulomb | C | As |
| Conductance | siemens | S | kg-1m-2s3A2 |
| Electromotive Force | volt | V | kgm2s-3A-1 |
| Energy | joule | J | kgm2s-2 |
| Force | newton | N | kgms-2 |
| Frequency | hertz | Hz | s-1 |
| Inductance | henry | H | kgm2s-2A-2 |
| Magnetic Flux | weber | Wb | kgm2s-2A-1 |
| Magnetic Flux Density | tesla | T | kgs-2A-1 |
| Power | watt | W | kgm2s-3 |
| Pressure | pascal | Pa | kgm-1s-2 |
| Resistance | ohm | Ω | kgm2s-3A-2 |
See also: Arbitrary Unit, Atomic Unit, Base Unit, CGS Units, Derived Units, Dimensions, Force, Unit, Velocity, Volume.
- Weblinks:
- International Standards Organisation Responsible for the world-wide publication of standards.
- National Institute of Standards and Technology USA based organisation.