The cubic meter is the unit of volume in the International System of Units. The symbol for cubic meters is m3. Less formally, cubic meter is sometimes abbreviated cu m.
When calculating volume, it is important to realize that volume is proportional to the cube of the linear dimension. Thus, if all linear dimensions are doubled, the volume becomes eight times (23) as great; if all linear dimensions are cut to 1/3, the volume becomes 1/27 (1/33) as great. A volume of 1 m3 is equal to 1,000,000 centimeters cubed (106 cm3) or 1,000,000,000 millimeters cubed (109 mm3). In the opposite sense, 1 m3 is equal to 0.000000001 kilometer cubed (10-9 km3).
When converting between cubic meters and non-SI units of volume such as cubic inches (cu in) or cubic miles (cu mi), the linear-unit conversion factor must be cubed. For example, one meter is approximately 39.37 inches (39.37 in); therefore 1 m3 = 39.373 = 6.102 x 104 cu in (approximately). As another example, 1 meter is about 0.0006215 mile (6.215 x 10-4 mi); therefore 1 m3 = (6.215 x 10-4)3 = 2.401 x 10-10 cu mi (approximately).