# Square_metre

# Square metre

SI-derived unit of area

The **square metre** (international spelling as used by the International Bureau of Weights and Measures) or **square meter** (American spelling) is the unit of area in the International System of Units (SI) with symbol **m ^{2}**.

^{[1]}It is the area of a square with sides one metre in length.

Adding and subtracting SI prefixes creates multiples and submultiples; however, as the unit is exponentiated, the quantities grow exponentially by the corresponding power of 10. For example, 1 kilometre is 10^{3} (one thousand) times the length of 1 metre, but 1 square kilometre is (10^{3})^{2} (10^{6}, one million) times the area of 1 square metre, and 1 cubic kilometre is (10^{3})^{3} (10^{9}, one billion) cubic metres.