Cubic Feet to Gallons Converter
A US liquid gallon is exactly 231 cubic inches and a cubic foot is exactly 1,728 of them, so cubic feet to gallons is one multiplication: gallons = cubic feet × 1728/231, a fraction that reduces to 576/77 and runs 7.48051948051948 and repeating in decimal. Nothing in that is measured, so the ratio is exact by definition: the international foot is defined as exactly 0.3048 metres and the US liquid gallon as exactly 3.785411784 litres, which is those 231 cubic inches. Only the decimal gets rounded, to twelve significant digits here, so 1 ft³ reads 7.48051948052 gal, 10 ft³ reads 74.8051948052 gal and 100 ft³, a stated CCF volume, reads 748.051948052 gal. The UK imperial gallon is a different and larger unit, exactly 4.54609 litres, so the same cubic foot is 6.22883545904 imperial gallons instead. This page opens the converter on the Volume category with cubic feet in the From box and US gallons in the To box, whatever pair you converted last, and under the answer it lists the same volume in millilitres, litres, cubic metres, teaspoons, tablespoons, US fluid ounces, cups, pints and quarts, with the imperial units and cubic inches behind the uncommon units switch.
- Category
- Volume
- Base unit
- liter
- Uncommon units
Spoons and cups are US customary measures. Imperial fluid ounces, pints and gallons have separate labeled entries; metric and Australian spoons are not separate units.
Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.
1 ft³ in every volume unit
Selectable complete conversion
Common questions
- How many gallons are in a cubic foot?
- The exact ratio is 1728/231 = 576/77 US liquid gallons per cubic foot. The display rounds it to 7.48051948052 gal. Thus 2 ft³ displays as 14.961038961 gal, 5 ft³ as 37.4025974026 gal and 10 ft³ as 74.8051948052 gal. Using 7.48 instead undercounts by about 0.00694%; for 100 ft³ it gives 748 gal rather than the displayed 748.051948052 gal, a difference of about 0.052 gal. Copy result copies the rounded headline without grouping commas; Copy complete conversion retains input, units and conventions and has selectable recovery.
- What is 100 cubic feet in gallons, the CCF on a water bill?
- When a bill defines CCF or HCF as 100 cubic feet, that volume displays here as 748.051948052 US liquid gallons (about 748 gal to the nearest whole gallon). A stated 6 CCF volume is 600 ft³: enter 600 to get 4,488.31168831 gal and 16,990.1079552 L. Check the bill’s stated volume convention; this converter does not calculate charges or infer a utility’s metering and rounding policy.
- How do I convert gallons back to cubic feet?
- Use the exact factor 231/1728 = 77/576 cubic feet per US liquid gallon. It displays as 0.133680555556 ft³ per gallon; multiplying by that already-rounded decimal is an approximation. The converter uses the defined ratio directly, so 50 gal displays as 6.68402777778 ft³ and 100 gal as 13.3680555556 ft³. Swap units reverses the pair without reloading and keeps the typed scalar number, reinterpreting it in the new From unit.
- Is this a US gallon or an imperial gallon?
- The To box here is the US liquid gallon, exactly 3.785411784 litres. The imperial gallon still used in the UK is exactly 4.54609 litres, about 20% larger, so one cubic foot is 6.22883545904 imperial gallons against 7.48051948052 US gallons. To see it, tick the uncommon units switch in the readout, which adds the imperial fluid ounce, imperial pint, imperial gallon and cubic inch to the list, or choose Gallon (imperial) in the To box, which lists every volume unit whether the switch is on or not.
- Does it matter whether the cubic feet hold water, fuel or air?
- No. This is a volume to volume conversion, so it is geometry and nothing else: a cubic foot of water and a cubic foot of air are both 7.48051948052 gallons of space. Weight is what changes with the contents, and that needs a density this converter does not carry, so its Mass category converts pounds, kilograms and ounces against each other rather than turning a volume into a weight.
- How do I work out the cubic feet in the first place?
- Multiply length by width by height with every measurement in feet. A tank 4 ft long, 2 ft wide and 2 ft deep is 16 ft³, and this page converts that to 119.688311688 gallons. If you measured in inches, divide the cubic inches by 1,728 first, since a foot is 12 inches and 12 × 12 × 12 = 1,728. For a cylinder, a cone or a pool with a sloping floor, the volume calculator linked below does the shape and prints US gallons next to the cubic feet.
- Why does the page open on cubic feet and gallons?
- This focused page opens on Cubic foot and Gallon (US), while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match the current From unit. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts do not overwrite the saved record. Unusable or conflicting records are kept with an explanation until you use Forget saved settings, which keeps the current conversion on screen.
Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.