**Metre** is base unit of length in International System of Units (SI).In SI unit metre symbol is **m**.
The metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second.

**Foot (ft)** is a unit of length in the imperial and US customary systems of measurement. Since 1959, both units have been defined by international agreement as equivalent to 0.3048 meters exactly. In both systems, the foot comprises 12 inches and three feet compose a yard.

**Inch (in or ″)** is a unit of length in the British imperial and United States customary systems of measurement.
The United States retains the 1 / 39.37 -metre definition for survey purposes

**Centimetre** is unit of length in metric system. Kilometre SI symbol is **cm**. One metre is equal to one hundred metre.

**Kilometre** is unit of length in metric system. Kilometre SI symbol is **km**. One kilometre is equal to one thousand metre.

**Mile ** is an English unit of length of linear measure equal to 5,280 feet, or 1,760 yards, and standardised
as exactly 1609.344 metres

**Yard (yd)** is an English unit of length, in both the British imperial and US customary systems of measurement, that comprises 3 feet or 36 inches. It is by international agreement in 1959 standardized as exactly 0.9144 meters