# Definition:SI Units

## Contents

## Definition

The **SI Units** are the elements of the International System of Units.

## SI Base Units

Name | Unit symbol | Dimension | Symbol |
---|---|---|---|

metre | $\mathrm m$ | Length | $l$ |

kilogram | $\mathrm {kg}$ | Mass | $m$ |

second | $\mathrm s$ | Time | $t$ |

ampere | $\mathrm A$ | Electric Current | $I$ |

kelvin | $\mathrm K$ | Temperature | $T$ |

candela | $\mathrm {cd}$ | Luminous Intensity | $I_v$ |

mole | $\mathrm {mol}$ | Amount of Substance | $n$ |

## SI Derived Units

The units derived from the SI base units include the following:

## Also see

## Historical Note

The SI units originated in the work done by Joseph Louis Lagrange to establish a decimal system for weights and measures.

## Linguistic Note

The abbreviation **SI** in the term **SI units** is from the French **Le Système International d'Unités** (**the International System of Units**).