Square kilometre

Square kilometre (U.S. spelling: square kilometer), symbol km², is a multiple of the SI derived unit of measure for area, the square metre.

1 km² is equal to:

• the area of a square measuring 1 kilometre on each side
• 1,000,000 square metres
• 100 hectares
• 0.386102 square statute miles
• 247.105381 acres

Conversely:

• 1 square metre = 0.000001 km²
• 1 hectare = 0.01 km²
• 1 square mile = 2.589988 km²
• 1 acre = 0.004047 km²

Note: "km²" means square kilometre and not kilo–square metre. For example, 3 km² is equal to 3 * (1,000 m)² = 3,000,000 m², not 3,000 m².

Other conversions are available from an Internet website provided by the National Institute of Standards and Technology.