| Base Quantity | Unit | Symbol |
|---|---|---|
| Length | metre | m |
| Mass | kilogram | kg |
| Time | second | s |
| Electric current | ampere | A |
| Temperature | kelvin | K |
| Amount of substance | mole | mol |
| Luminous intensity | candela | cd |
Supplementary units (now derived): radian (plane angle), steradian (solid angle).
Key derived units with special names: Newton (N = kgm/s^2), Joule (J = Nm), Watt (W = J/s), Pascal (Pa = N/m^2), Hertz (Hz = s^{-1}), Coulomb (C = A*s), Volt (V = J/C), Ohm (Omega = V/A).