There are 264.172052 gallons in a cubic meter. To convert cubic meters to gallons, multiply the cubic meter value by 264.172052. For example, to find out how many gallons in a cubic meter and a half, multiply 1.5 by 264.172052, that makes 396.258 gallons in a cubic meter and a half. cubic meters to US gallons formula. gallon = m³ * 264.172052
