The square meter, also called the meter squared, is the Standard International (SI) unit of area. The symbol for square meter is m2. Less formally, square meter is sometimes abbreviated sq m.
When calculating area, it is important to realize that area is proportional to the square of the linear dimension. Thus, if all linear dimensions are doubled, the area becomes four times (22) as great; if all linear dimensions are cut to 1/3, the area becomes 1/9 (1/32) as great. An area of 1 m2 is equal to 10,000 centimeters squared (104 cm2) or 1,000,000 millimeters squared (106 mm2). In the opposite sense, 1 m2 is equal to 0.000001 kilometer squared (10-6 km2).
When converting between square meters and non-SI units of area such as square inches (sq in) or square miles (sq mi), the linear-unit conversion factor must be squared. For example, one meter is approximately 39.37 inches (39.37 in); therefore 1 m2 = 39.372 = 1550 sq in (approximately). As another example, 1 meter is about 0.0006215 mile (6.215 x 10-4 mi); therefore 1 m2 = (6.215 x 10-4)2 = 3.863 x 10-7 sq mi (approximately).
Also see meter, cubic meter, and Standard International (SI) System of Units.