Symbol: **km²**

Unit System: SI

Unit System: SI

The square kilometre is a unit of area and is a multiple of the square metre; an SI derived unit. It has the symbol km².

A square kilometre is equal to the area of a square with edges 1km long. There are 1,000,000 square metres in a square kilometre.

Square kilometres are often used to describe expansive areas of land due to the large unit size.