# Meter

### From Fiswiki

**Metre** (or ** meter**), symbol

**m**, is the base unit of length in the International System of Units (SI). Originally intended to be one ten-millionth of the distance from the Earth's equator to the

**North Pole**, its definition of has been periodically refined to reflect growing knowledge of

**metrology**. Since 1983, it is defined as the distance travelled by light in a complete vacuum in

**1⁄299,792,458**of a

**second**.

Reference *Meter* [1]