Square kilometre
Square kilometre (International spelling as used by the International Bureau of Weights and Measures) or square kilometer (American spelling), symbol km2, is a multiple of the square metre, the SI unit of area or surface area. 1 km2 is equal to: * 1,000,000 square metres (m2) * 100 hectares (ha) It is also approximately equal to: * 0.3861 square miles * 247.1 acres Conversely: * 1 m2 = 0.000001 (10−6) km2 * 1 hectare = 0.01 (10−2) km2 * 1 square mile = 2.5899 km2 * 1 acre = about 0.004047 km2 The symbol "km2" means (km)2, square kilometre or kilometre squared and not k(m2), kilo–square metre. For example, 3 km2 is equal to 3×(1,000m)2 = 3,000,000 m2, not 3,000 m2. (Wikipedia).
