Though the cubic meter is the standard unit of volume in the metric system, litres are also frequently used and acceptable within the metric system. Meters cubed are derived from the meter, the metric system's unit form measuring length. When these three dimensions, each measured in meters, are multiplied, the resulting unit of measure is meters cubed. The litre is defined as one thousandth of a cubic meter, or one cubic decimetre. This relationship allows easy conversion between litres and meters cubed.

Write the formula for converting volume from litres to cubic meters: meters cubed equals litres divided by 1,000 (m^3 = L ÷ 1,000).

Write the volume in litres. Divide the volume in litres by 1,000 to yield the volume in meters cubed. For example, a volume of 15 litres equals 0.015 cubic meters (15 L ÷ 1000 = 0.015m^3).

Convert back to litres from cubic meters by multiplying the volume in cubic meters by 1000 (L = m^3 x 1000). Using the previous example, a volume of 0.015 cubic meters equals 15 litres (0.015m^3 x 1,000 = 15 L).