A cubic foot is exactly 0.028316846592 cubic meters.
Cubic feet to Gallons Converter — ft3 to gal
Convert Cubic foot (ft3) to Gallon (gal) using the exact conversion factor (1 cubic foot = 7.480519481 gallon). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Cubic feet to Gallons 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 US liquid gallon is exactly 3.785411784 liters.
Result = input x 0.02831684659 / 0.003785411784.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Cubic feet to Gallons
Cubic foot and Gallon 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. Cubic foot is typically associated with united States (construction, HVAC, natural gas billing), while Gallon is typically associated with united States (fuel, beverage, and liquid measurement).
Formula
gallons = cubic feet × 7.48051948052
This factor comes from each unit's defined relationship to the category's base unit: 1 cubic foot equals 0.028316846592 base units, and 1 gallon equals 0.003785411784 base units, so dividing one by the other gives the direct cubic foot-to-gallon factor of 7.48051948052.
Simple example
1 ft3 × 7.480519481 = 7.480519481 gal
1 cubic foot = 7.480519481 gallons.
Real-world example
10 ft3 × 7.480519481 = 74.80519481 gal
10 cubic feet = 74.80519481 gallons.
Conversion table
| Cubic foot (ft3) | Gallon (gal) |
|---|---|
| 1 ft3 | 7.480519481 gal |
| 5 ft3 | 37.4025974 gal |
| 10 ft3 | 74.80519481 gal |
| 25 ft3 | 187.012987 gal |
| 50 ft3 | 374.025974 gal |
| 100 ft3 | 748.0519481 gal |
Reverse conversion: Gallon to Cubic foot
7.480519481 gal × 0.1336805556 = 1 ft3
7.480519481 gallons = 1 cubic feet.
cubic feet = gallons × 0.133680555556
For a page dedicated to this direction, see Gallon to Cubic foot.
Cubic foot vs. Gallon
| Aspect | Cubic foot | Gallon |
|---|---|---|
| Family | US/imperial customary unit | US customary unit |
| Typical use | US natural gas utility billing (often in hundreds or thousands of cubic feet) | Fuel pump and vehicle fuel-economy measurement in the US |
| Where it's used | United States (construction, HVAC, natural gas billing) | United States (fuel, beverage, and liquid measurement) |
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.
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.
Cubic foot — sources
- NIST — International yard and pound (1959) — Basis for the modern foot and its derived volume unit.
Gallon — sources
- NIST Handbook 44, Appendix C — General tables of units of measurement, including the US gallon definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many gallons are in 1 cubic foot?
1 cubic foot equals 7.480519481 gallons, using the exact defined conversion factor rather than an estimate.
How do I convert cubic foot to gallon?
Multiply the cubic foot value by 7.480519481. The converter above does this instantly to whatever precision you set.
How do I convert gallon back to cubic foot?
Use the reverse factor: 1 gallon equals 0.1336805556 cubic feet. You can also use the swap control in the converter above to flip the direction instantly.
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.
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.
Is the cubic foot to gallon conversion exact?
Yes. The US liquid gallon is defined as exactly 231 cubic inches, equal to 3.785411784 liters. 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 cubic foot still used today?
United States (construction, HVAC, natural gas billing)