The units of length which are bigger than a metre are —
- Astronomical Unit (A.U.) — One astronomical unit is equal to the mean distance between the earth and the sun. Relation between metre and astronomical unit is expressed as: A.U. = 1.496 x 1011m
- Light year (ly) — A light year is the distance travelled by light in vacuum, in one year. Relation between metre and light year is expressed as: 1 light year = 9.46 x 1015m