US gallons to Cubic feet Converter
Convert US gallons (gal) to Cubic feet (ft³) instantly, or use the conversion table below to look up common values.
US gallons to Cubic feet conversion table
| US gallons (gal) | Cubic feet (ft³) |
|---|---|
| 1 | 0.133681 |
| 2 | 0.267361 |
| 3 | 0.401042 |
| 4 | 0.534722 |
| 5 | 0.668403 |
| 10 | 1.336806 |
| 25 | 3.342014 |
| 50 | 6.684028 |
| 100 | 13.368056 |
How to convert US gallons to Cubic feet
1 gal equals 0.133681 ft³. Use the converter above for any value, or read the table for common conversions.
ft³ = gal × 0.13368055555555555 · gal = ft³ × 7.480519480519481Multiply a us gallons figure by 0.133681 to get cubic feet, or divide it by 7.480519 to go the other way.
Worked examples
- 1 gal= 0.133681 ft³
- 2 gal= 0.267361 ft³
- 5 gal= 0.668403 ft³
- 10 gal= 1.336806 ft³
- 20 gal= 2.673611 ft³
What these units are
US gallons (gal). A US gallon is 3.785411784 liters, defined as 231 cubic inches. It is the standard liquid and fuel unit in the United States, and is about 20% smaller than an imperial gallon.
Cubic feet (ft³). A cubic foot is 28.316846592 liters, and the volume of a cube one foot on each side. It is used for gas meters, freight and the capacity of appliances and containers.
US and imperial units are kept separate because they are genuinely different sizes. Confirm which system a source means before trusting a converted figure.
Converting US gallons to Cubic feet in practice
Working in us gallons
A US gallon is exactly 3.785411784 liters, or 231 cubic inches, and it divides into four quarts, eight pints or 128 US fluid ounces. It is a defined liquid volume and not a unit of mass.
Fuel at filling stations, paint, milk, water and agricultural sprays are sold by the US gallon in the United States and in some export markets. Larger tanks and drums are also rated in gallons.
The site uses the US gallon of exactly 3.785411784 liters; the imperial gallon is exactly 4.54609 liters and is roughly a fifth larger. Display rounding can move the final digit of a gallon to liter conversion taken both ways.
The frequent mistake is applying the imperial gallon to a US figure or the reverse, which misstates fuel or tank volume by around a fifth. A gallon also measures volume, while a gallon of a specific liquid has a mass.
The US gallon belongs with quarts, pints and fluid ounces, while the imperial gallon and the liter sit on other scales. Fuel is sold by the gallon in some markets and by the liter in others, so a consumption figure must be converted first.
Reading the result in cubic feet
A cubic foot is the volume of a cube with edges one foot long, exactly 28.316846592 liters or 0.028316846592 cubic meters. It is a unit of volume, not of area.
Shipping containers, natural gas, water supply, refrigeration and timber are measured in cubic feet in the United States and parts of the freight trade. Appliance capacities also use it.
The cubic foot is defined through the foot, so its liter value is exact at 28.316846592. Only the displayed result is rounded, and a value taken to cubic meters and back may return with the final digit changed.
The error is confusing a cubic foot with a square foot or with a foot; volume needs three dimensions. Another is using the cubic foot where a liquid measure such as the liter or gallon is expected.
Cubic feet and cubic meters divide the same volume on different scales, and liters appear on appliance and gas labels. One cubic meter is about 35.3 cubic feet, so a figure copied between them without conversion is wrong by more than thirtyfold.
Checking a us gallons to cubic feet conversion
The metric volume units are a clean decimal chain around the liter, so liters to milliliters is a shift of three places and cubic meters to liters is a shift of three the other way. Those pairs a reader can do without a converter.
Every pair that names a US or imperial liquid unit has to go through the definition first, because three of these units differ from a metric unit by amounts too large to round away: a liter is not a quart, a gallon is 3.785411784 liters in the US system and 4.54609 in the imperial one, and a US fluid ounce is not an imperial fluid ounce.
When checking a volume conversion, convert into liters and out again, or measure the container. The mistake that survives every other check is reading a US measure as the imperial unit of the same name, which changes a recipe, a fuel figure or a tank size by about a fifth.
Tanzania reference points
Real quantities, converted into the units on this page.
The 20-litre bucket or canister used to carry water in Tanzania
20 L = 5.283441 gal = 0.706293 ft³
WaterAid puts the minimum daily water need per person at 20 litres, so one container is roughly one person's daily requirement.
Source: IPS News — water access in Tanzania, citing WaterAid · verified 2026-09-14
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