The cubic meter is the SI unit of volume, the space inside a cube measuring 1 m along each edge. NIST's table gives the liter as exactly 0.001 m³, so a cubic meter holds exactly 1,000 liters, or 1,000,000 milliliters.
Formula
m³ = length (m) × width (m) × height (m)
L = m³ × 1,000
ft³ = m³ × 35.3147 (1 ÷ 0.3048³)
yd³ = m³ × 1.30795 (1 ÷ 0.9144³)
Example
A tank 2 m × 1.5 m × 0.8 m holds 2 × 1.5 × 0.8 = 2.4 m³, which is 2,400 L. In US units that is 2.4 × 35.3147 = 84.8 ft³ or 2.4 × 1.30795 = 3.14 yd³.
Common mistakes
A cubic meter is 100 × 100 × 100 = 1,000,000 cm³, not 100 cm³. Likewise 1 m³ is 1,000 liters, not 100. See how many ml in a liter for the liter step, and the volume calculator for shapes.