SI units are to be preferred in all technical works. Units from other schemes may be given for reference or where such units are still commonly used on a worldwide basis. The casing used in abbreviations of units is important.
| Quantity | Unit | Symbol | |
|---|---|---|---|
| Time | second | s |
| Length | metre | m |
| Mass | kilogram | kg |
| Electric current | ampere | A |
| Thermodynamic temperature | kelvin | K |
| Amount of substance | mole | mol |
| Luminous intensity | candela | cd |
| Plane angle | radian | rad |
| Solid angle | steradian | sr |
The unit which is one thousandth of a kilogram is the gram (g)
| Quantity | Unit | Symbol | Base units |
|---|---|---|---|
| Area | square metre | m² | m² |
| Volume | cubic metre | m³ | m³ |
| Frequency | hertz | Hz | s-1 |
| Density | kilogram per cubic metre | kgm-3 | kgm-3 |
| Velocity | metre per second | ms-1 | ms-1 |
| Angular velocity | radian per second | rads-1 | rads-1 |
| Acceleration | metre per second squared | ms-2 | ms-2 |
| Angular acceleration | radian per second squared | rads-2 | rads-2 |
| Volumetric flow rate | cubic metre per second | m³s-1 | m³s-1 |
| Momentum and impulse | kilogram metre per second | kgms-1 | kgms-1 |
| Force | newton | N | kgms-2 |
| Surface tension | newton per metre | Nm-1 | kgs-2 |
| Pressure | pascal | Pa | kgms-2 |
| Dynamic viscosity | pascal second | Pas | kgms-1 |
| Kinematic viscosity | square metre per second | m²s-1 | m²s-1 |
| Energy, work, torque and quantity of heat | joule | J | kgm²s-2 |
| Power and heat flux | watt | W | kgm²s-3 |
| Heat flux density | watt per square metre | Wm-2 | kgs-3 |
| Volumetric heat release rate | watt per cubic metre | Wm-3 | kgm-1s-3 |
| Heat transfer coefficient | watt per square metre per kelvin | Wm-2K-1 | kgs-3K-1 |
| Thermal conductivity | joule per second per metre per kelvin | Js-1m-1K-1 | kgms-3K-1 |
| Specific heat capacity | joule per kilogram per kelvin | J(kg)-1K-1 | m²s²K-1 |
| Electric charge | coulomb | C | As |
| Electric field strength | newton per coulomb | NC-1 | kgmA-1s-3 |
| Electromotive force | volt | V | kgm²A-1s-3 |
| Electric resistance | ohm | ω | kgm²A-2s-3 |
| Electric conductance | siemens | S | A²s³(kg)-1m² |
| Electric conductivity | siemens per metre | Sm-1 | A²s³(kg)-1m-3 |
| Electric capacitance | farad | F | A²s4(kg)-1m-2 |
| Magnetic flux | weber | Wb | kgm²A-2s-2 |
| Magnetic flux density | tesla | T | kgA-2s-2 |
| Magnetic field strength | ampere per metre | Am-1 | Am-1 |
| Inductance | henry | H | kgm²A-2s-2 |
| Magnetic permeability | henry per metre | Hm-1 | kgm²A-2s-2 |
| Magnetomotive force | ampere | A | A |
| Luminous flux | lumen | lm | cdsr |
| Luminance | candela per square metre | cdm-2 | cdm-2 |
| Illumination | lux | lx | cdsrm-2 |
| Activity (of radionuclides) | bequerel | Bq | s-1 |
| Absorbed dose | gray | Gy | m²s-2 |
| Dose equivalent | sievert | Sv | m²s-2 |
| Quantity | Unit | Named after |
|---|---|---|
| Frequency | hertz | Heinrich Hertz |
| Force | newton | Sir Isaac Newton |
| Pressure | pascal | Blaise Pascal |
| Energy, work, torque and quantity of heat | joule | James P. Joule |
| Power and heat flux | watt | James Watt |
| Electric charge | coulomb | Charles A. Coulomb |
| Electromotive force | volt | Alessandro Volta |
| Electric resistance | ohm | Georg Ohm |
| Electric conductance | siemens | Sir William Siemens |
| Electric capacitance | farad | Michael Faraday |
| Magnetic flux | weber | Wilhelm Weber |
| Magnetic flux density | tesla | Nikola Tesla |
| Inductance | henry | Joseph Henry |
| Luminous flux | lumen | – |
| Illumination | lux | – |
| Activity (of radionuclides) | bequerel | Antoine H. Becquerel |
| Absorbed dose | gray | L.H. Gray |
| Dose equivalent | sievert | – |
See also: ASCII Gamut, Important Unicode Characters and SI Unit Prefixes.
Last updated: Thursday 5th August 2004