Gallons to Cubic Meters Converter

Gallons and cubic meters for metric pool volumes

Pool volumes outside the US are usually quoted in cubic meters rather than gallons -- a 20,000 gallon pool is about 75.7 cubic meters. Cubic meters is also how many imported pumps and heaters rate their flow (cubic meters per hour instead of gallons per minute), so this converter is most useful when you're comparing a metric spec sheet against a US-built calculator that expects gallons.

The exact factor is 1 US gallon = 0.003785411784 cubic meters, which follows directly from 1 gallon = 3.785411784 liters and 1 cubic meter = 1,000 liters. Reverse it (divide by the factor, or multiply by 264.172) to go from cubic meters back to gallons.

Once you have your pool's volume in gallons, every calculator in the Chemicals section -- salt, chlorine, shock, pH and alkalinity dosing -- is ready to use, since all of them are written in gallons.

Where these numbers come from

The formulas and default values in this calculator are based on:

• NIST Handbook 44 and SI unit conversion factors (1 US gallon = 3.785411784 liters
• 1 cubic meter = 1,000 liters, giving 0.003785411784 cubic meters per gallon)

These are planning estimates. Test your actual water, follow product labels, and check your equipment manufacturer's guidance before you buy or dose chemicals.