A US liquid gallon is exactly 3.785411784 liters.
Gallons to Cubic feet Converter — gal to ft3
Convert Gallon (gal) to Cubic foot (ft3) using the exact conversion factor (1 gallon = 0.1336805556 cubic foot). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Gallons to Cubic feet converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
A cubic foot is exactly 0.028316846592 cubic meters.
Result = input x 0.003785411784 / 0.02831684659.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Gallons to Cubic feet
Gallon and Cubic foot appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Gallon is typically associated with united States (fuel, beverage, and liquid measurement), while Cubic foot is typically associated with united States (construction, HVAC, natural gas billing).
Formula
cubic feet = gallons × 0.133680555556
This factor comes from each unit's defined relationship to the category's base unit: 1 gallon equals 0.003785411784 base units, and 1 cubic foot equals 0.028316846592 base units, so dividing one by the other gives the direct gallon-to-cubic foot factor of 0.133680555556.
Simple example
1 gal × 0.1336805556 = 0.1336805556 ft3
1 gallon = 0.1336805556 cubic feet.
Real-world example
10 gal × 0.1336805556 = 1.336805556 ft3
10 gallons = 1.336805556 cubic feet.
Conversion table
| Gallon (gal) | Cubic foot (ft3) |
|---|---|
| 1 gal | 0.1336805556 ft3 |
| 5 gal | 0.6684027778 ft3 |
| 10 gal | 1.336805556 ft3 |
| 25 gal | 3.342013889 ft3 |
| 50 gal | 6.684027778 ft3 |
| 100 gal | 13.36805556 ft3 |
Reverse conversion: Cubic foot to Gallon
0.1336805556 ft3 × 7.480519481 = 1 gal
0.1336805556 cubic feet = 1 gallons.
gallons = cubic feet × 7.48051948052
For a page dedicated to this direction, see Cubic foot to Gallon.
Gallon vs. Cubic foot
| Aspect | Gallon | Cubic foot |
|---|---|---|
| Family | US customary unit | US/imperial customary unit |
| Typical use | Fuel pump and vehicle fuel-economy measurement in the US | US natural gas utility billing (often in hundreds or thousands of cubic feet) |
| Where it's used | United States (fuel, beverage, and liquid measurement) | United States (construction, HVAC, natural gas billing) |
Understanding the Gallon
Gallon (gal) measures volume. The US liquid gallon is defined as exactly 231 cubic inches, equal to 3.785411784 liters. It is classified as a US customary unit.
Where it's used: United States (fuel, beverage, and liquid measurement)
US gallon vs. imperial gallon. The US liquid gallon (3.785411784 L) and the British imperial gallon (4.54609 L) are different units with the same name; always confirm which one a source is using.
Uses of the Gallon today
- Fuel pump and vehicle fuel-economy measurement in the US
- Beverage and liquid product packaging in the US
- Cooking and recipe measurement in US customary units
History of the Gallon
The US gallon descends from the English wine gallon of 231 cubic inches, a standard used for measuring wine in medieval and early modern England, which the American colonies inherited and retained even after England moved to a different imperial gallon in 1824.
England's 1824 Weights and Measures Act replaced the old wine gallon with a new imperial gallon (based on 10 pounds of water), but the US kept the older 231-cubic-inch definition — which is why the US gallon (3.785 L) and the imperial gallon (4.546 L) differ by about 20% today.
Historical origin. Gallon was not the invention of a single named person; it developed through the process described above.
Understanding the Cubic foot
Cubic foot (ft3) measures volume. A cubic foot is exactly 0.028316846592 cubic meters, derived from the 1959 international foot. It is classified as a US/imperial customary unit.
Where it's used: United States (construction, HVAC, natural gas billing)
Uses of the Cubic foot today
- US natural gas utility billing (often in hundreds or thousands of cubic feet)
- HVAC airflow and building-volume calculations
- Lumber, concrete, and construction material estimation in the US
History of the Cubic foot
The cubic foot, like the square foot, follows from the standardized foot (exactly 0.3048 m since the 1959 international agreement) rather than having a separate historical definition.
Historical origin. Cubic foot was not the invention of a single named person; it developed through the process described above.
Gallon — sources
- NIST Handbook 44, Appendix C — General tables of units of measurement, including the US gallon definition.
Cubic foot — sources
- NIST — International yard and pound (1959) — Basis for the modern foot and its derived volume unit.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many cubic feet are in 1 gallon?
1 gallon equals 0.1336805556 cubic feet, using the exact defined conversion factor rather than an estimate.
How do I convert gallon to cubic foot?
Multiply the gallon value by 0.1336805556. The converter above does this instantly to whatever precision you set.
How do I convert cubic foot back to gallon?
Use the reverse factor: 1 cubic foot equals 7.480519481 gallons. You can also use the swap control in the converter above to flip the direction instantly.
What is a gallon?
Gallon (gal) measures volume. The US liquid gallon is defined as exactly 231 cubic inches, equal to 3.785411784 liters. It is classified as a US customary unit.
What is a cubic foot?
Cubic foot (ft3) measures volume. A cubic foot is exactly 0.028316846592 cubic meters, derived from the 1959 international foot. It is classified as a US/imperial customary unit.
Is the gallon to cubic foot conversion exact?
Yes. A cubic foot is exactly 0.028316846592 cubic meters, derived from the 1959 international foot. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between us gallon vs. imperial gallon?
The US liquid gallon (3.785411784 L) and the British imperial gallon (4.54609 L) are different units with the same name; always confirm which one a source is using.
Where is the gallon still used today?
United States (fuel, beverage, and liquid measurement)