Square metre


 * M^2 redirects here. For other uses, see M².



The square metre (also spelt meter, see spelling differences) is the SI derived unit of area, with symbol m². It is defined as the area of a square whose sides measure exactly one metre. The square metre is derived from the SI base unit of the metre, which in turn is defined as the length of the path travelled by light in absolute vacuum during a time interval of $1⁄299,792,458$ of a second.

Adding SI prefixes creates multiples and submultiples; however, as the unit is squared, the order of magnitude difference between units doubles from their comparable linear units. For example, a kilometre is one thousand times the length of a metre, but a square kilometre is one million times the area of a square metre.

SI prefixes applied to the square metre
The square metre may be used with all SI prefixes used with the metre.

Conversions
A square metre is equal to:
 * 0.000 001 square kilometre (km²)
 * 10,000 square centimetres (cm²)
 * 0.000 1 hectares (ha)
 * 0.01 ares (a)
 * 1 centiare (ca)
 * 0.000 247 105 381 acres
 * 1.195 990 square yards
 * 10.763 911 square feet
 * 1,550.003 1 square inches