Square kilometre

A square kilometer (British English spelling square kilometre, in short km²) is a unit of measurement of area.
It is based on the SI unit meter.

 Equal areas 
A square that has a side length of 1 kilometer (1000 meters) has an area of one square kilometer.
 1,000 m × 1,000 m = 1 km × 1 km = 1,000,000 m² = 1 km²
There are 100 hectares in one square kilometer.
One square kilometer is just less than 0.39 square miles.

 Use 
Square kilometer is often used to say how much surface something occupies on Earth.
It can, for example, be used to describe the area of a city or country.
These usually take more than 1 km² on Earth.

The number of people living in a square kilometer is known as population density.

 Sources 

Category:Units of area