Convert U.S. gal to ft³ Instantly
Use this Gallons to Cubic Feet converter to change U.S. liquid gallons into cubic feet for tanks, water storage, containers, landscaping, construction and general volume calculations. One U.S. liquid gallon equals approximately 0.133680556 cubic feet, while one cubic foot contains approximately 7.48051948 U.S. gallons.
Convert U.S. gallons to cubic feet, reverse cubic feet to gallons, convert Imperial gallons, or compare one volume across gallons, liters, cubic feet, cubic yards and cubic meters.
Enter U.S. liquid gallons to calculate cubic feet, cubic yards, liters and cubic meters.
Use U.S. liquid gallons. Decimals are supported.
Enter cubic feet to calculate U.S. gallons, Imperial gallons, liters and cubic yards.
Convert UK/Imperial gallons to cubic feet without mixing the U.S. and Imperial gallon standards.
Convert one value across U.S. gallons, Imperial gallons, cubic feet, cubic yards, liters and cubic meters.
Gallons and cubic feet are both units of volume, but they are used in different situations. Gallons are commonly used for liquid capacity, while cubic feet are common for tanks, storage spaces, appliances, HVAC calculations, soil, construction materials and three-dimensional measurements. Converting between the two allows you to compare a liquid capacity with a geometric volume.
A U.S. liquid gallon contains exactly 231 cubic inches. One cubic foot contains 1,728 cubic inches. Dividing 231 by 1,728 gives approximately 0.1336805556 cubic foot per U.S. gallon.
Example: 100 gal × 0.1336805556 ≈ 13.36805556 ft³.
Example: 10 ft³ × 7.4805194805 ≈ 74.80519481 gal.
Gallons are familiar for water, fuel, tanks, ponds, aquariums and container capacity.
Cubic feet describe a three-dimensional volume measuring one foot by one foot by one foot.
Multiply gallons by 0.1336805556 or multiply cubic feet by 7.4805194805.
Use the separate Imperial-gallon panel when the source specifically uses UK gallons.
This chart shows common U.S. liquid gallon values converted to cubic feet, liters and cubic yards.
| U.S. Gallons | Cubic Feet | Liters | Cubic Yards |
|---|---|---|---|
| 1 gal | 0.133681 ft³ | 3.785412 L | 0.004951 yd³ |
| 5 gal | 0.668403 ft³ | 18.927059 L | 0.024756 yd³ |
| 10 gal | 1.336806 ft³ | 37.854118 L | 0.049511 yd³ |
| 20 gal | 2.673611 ft³ | 75.708236 L | 0.099023 yd³ |
| 25 gal | 3.342014 ft³ | 94.635295 L | 0.123778 yd³ |
| 50 gal | 6.684028 ft³ | 189.270589 L | 0.247557 yd³ |
| 75 gal | 10.026042 ft³ | 283.905884 L | 0.371335 yd³ |
| 100 gal | 13.368056 ft³ | 378.541178 L | 0.495113 yd³ |
| 200 gal | 26.736111 ft³ | 757.082357 L | 0.990226 yd³ |
| 250 gal | 33.420139 ft³ | 946.352946 L | 1.237783 yd³ |
| 500 gal | 66.840278 ft³ | 1,892.705892 L | 2.475566 yd³ |
| 1,000 gal | 133.680556 ft³ | 3,785.411784 L | 4.951132 yd³ |
5 × 0.1336805556 ≈ 0.668403 ft³.
10 × 0.1336805556 ≈ 1.336806 ft³.
25 × 0.1336805556 ≈ 3.342014 ft³.
50 × 0.1336805556 ≈ 6.684028 ft³.
100 × 0.1336805556 ≈ 13.368056 ft³.
A cubic foot is a cube measuring 12 inches on each side, so it contains 12 × 12 × 12 = 1,728 cubic inches. A U.S. liquid gallon contains 231 cubic inches. Dividing 1,728 by 231 gives approximately 7.4805194805 gallons per cubic foot. This relationship is useful whenever a container is measured geometrically in feet but liquid capacity is required in gallons.
The reverse is 1 gal ≈ 0.133680556 ft³.
The U.S. liquid gallon equals exactly 231 cubic inches, or 3.785411784 liters. One U.S. gallon is approximately 0.133680556 cubic foot.
The Imperial gallon equals exactly 4.54609 liters. Because it is larger than a U.S. gallon, one Imperial gallon is approximately 0.160543653 cubic foot.
Water tanks are often sold by gallon capacity, while the space available for installation may be measured in feet. Converting gallons to cubic feet provides a quick way to compare the nominal liquid capacity with a geometric volume. For example, a 500-gallon volume is approximately 66.8403 ft³.
The outside dimensions of a real tank will usually occupy more space than the converted liquid volume because walls, fittings, freeboard, insulation, structural supports and curved surfaces add to the exterior envelope. Use the conversion for capacity comparison, not as a substitute for manufacturer dimensions.
Aquarium and pond projects often move between dimensions and liquid capacity. If the capacity is known in gallons, this converter gives the equivalent cubic-foot volume. If the length, width and depth are known in feet, first calculate cubic feet and then use the reverse calculator to estimate U.S. gallons.
For irregular ponds, sloped sides, rock displacement and changing water depth can make a simple rectangular volume estimate inaccurate. Use measured dimensions or a project-specific pond formula before converting units.
Construction and landscaping calculations sometimes combine liquid volume and geometric volume. Water storage, curing water, irrigation, soil amendments, liquid treatments and container capacities may be specified in gallons while site drawings or storage areas use cubic feet. Converting to one common unit helps compare quantities.
If your project later needs larger bulk-volume units, use the Gallons to Cubic Yards converter or a Cubic Feet to Cubic Yards converter. For metric comparisons, the Liters to Cubic Feet converter is a natural companion tool.
One cubic foot contains 1,728 cubic inches, which is approximately 7.48052 U.S. liquid gallons.
| Cubic Feet | U.S. Gallons | Imperial Gallons | Liters |
|---|---|---|---|
| 1 ft³ | 7.480519 gal | 6.228835 Imp gal | 28.316847 L |
| 2 ft³ | 14.961039 gal | 12.457671 Imp gal | 56.633693 L |
| 5 ft³ | 37.402597 gal | 31.144177 Imp gal | 141.584233 L |
| 10 ft³ | 74.805195 gal | 62.288355 Imp gal | 283.168466 L |
| 20 ft³ | 149.610390 gal | 124.576709 Imp gal | 566.336932 L |
| 50 ft³ | 374.025974 gal | 311.441773 Imp gal | 1,415.842330 L |
| 100 ft³ | 748.051948 gal | 622.883546 Imp gal | 2,831.684659 L |
One cubic yard contains exactly 27 cubic feet. Combining that relationship with 7.48051948 U.S. gallons per cubic foot means one cubic yard contains approximately 201.974026 U.S. gallons. This is useful when a project moves from liquid-capacity units into construction-scale volume.
This chain is useful for tanks, water storage and bulk-site planning.
One U.S. liquid gallon equals exactly 3.785411784 liters. Because one cubic meter contains exactly 1,000 liters, a 100-gallon volume is 378.5411784 liters or about 0.3785411784 cubic meter. The multi-unit calculator above displays these values automatically.
For related metric conversions, use our Liters to Cubic Feet, Liters to Cubic Meters, or Liters to Cubic Yards tools.
U.S. and Imperial gallons are different sizes. Identify the gallon standard before converting.
Multiply ft³ by 7.48052 to get gallons. Divide gallons by 7.48052 to get ft³.
Square feet measure area; cubic feet measure volume. A gallon cannot be converted directly to square feet without a depth.
Keep several digits through intermediate calculations, then round the final answer to suitable precision.
Continue with the Gallons to Cubic Yards converter, Liters to Cubic Feet, Liters to Cubic Meters, Cubic Centimeters to Cubic Inches, Milliliters to Cubic Inches and Liters to Cubic Yards.
For official U.S. measurement relationships and unit-conversion guidance, see NIST guidance on volume units and the NIST Guide for the Use of the International System of Units. These references are useful when checking relationships between customary and metric volume units.
Quick answers about U.S. gallons, cubic feet, tank capacity and reverse volume conversions.