Convert US Gallon to Cubic Foot (gal (US)ft³)

The US gallon is the standard unit for fuel, milk, and beverages across the United States.

0.133681
1 gal (US)0.133681 ft³NIST · BIPM accuracy

US Gallon to Cubic Foot Conversion Table

10 common values
US GallonCubic Foot
1 gal (US)0.133681 ft³
2 gal (US)0.267361 ft³
5 gal (US)0.668403 ft³
10 gal (US)1.336806 ft³
20 gal (US)2.673611 ft³
50 gal (US)6.684028 ft³
100 gal (US)13.368056 ft³
200 gal (US)26.736111 ft³
500 gal (US)66.840278 ft³
1,000 gal (US)133.68056 ft³

How to Convert US Gallon to Cubic Foot Manually

Step by Step

Converting US gallons to cubic feet is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

  1. 1
    Take your value in US gallons
    Start with the number of US gallons (gal (US)) you want to convert.
  2. 2
    Multiply by 0.133681
    The conversion factor from gal (US) to ft³ is 0.133681. Multiply your value by this number.
  3. 3
    Read the result in cubic feet
    The result is your value in cubic feet (ft³).
Practical Examples
1 gal (US)
equals
0.133681 ft³
5 gal (US)
equals
0.668403 ft³
10 gal (US)
equals
1.336806 ft³
25 gal (US)
equals
3.342014 ft³
100 gal (US)
equals
13.368056 ft³

Formula

Multiply the value in US gallons by 0.133681. For the reverse direction, multiply by 7.48052.

Forwardft³ = gal (US) × 0.133681
Reversegal (US) = ft³ × 7.48052
Example: 10 gal (US) × 0.133681 = 1.336806 ft³

Tips

Use these in everyday conversions
  • 1 US gallon = 3.785 L = 128 US fluid ounces = 4 quarts.
  • Converting mpg (US) to L/100 km: 235.215 / mpg = L/100 km.
  • The US gallon is based on the old English Queen Anne wine gallon (1707).

Common Mistakes

Avoid these
  • Using UK gallons on a US fuel-economy figure — 30 mpg (US) = 36 mpg (UK).
  • Confusing US gallon (3.79 L) with UK gallon (4.55 L) — 20% difference.
  • Using "gallon" without qualifier in cross-Atlantic commerce.

About US Gallon and Cubic Foot

What is the US Gallon?

The US liquid gallon equals exactly 3.785411784 liters and is the standard volume unit for fuel, beverages, milk, and household liquids in the United States. Defined as 231 cubic inches, the US gallon descends from the English wine gallon of 1707, which Britain replaced with the larger imperial gallon in 1824 — a divergence that left the United States with a different gallon than the rest of the English-speaking world. American gas stations price gasoline by the gallon (typical fill-up: 12–15 gallons), milk is sold in half-gallons and gallons, and many beverages come in fluid-ounce subdivisions of the gallon. The US gallon relates to the liter (1 gal ≈ 3.785 L), the quart (4 qt = 1 gal), the pint (8 pt = 1 gal), the cup (16 cups = 1 gal), and the imperial gallon (1 imp gal ≈ 1.201 US gal — about 20% larger).

  • US fuel pricing and consumption
  • US paint, oil and cleaning-product packaging
  • US beverage containers (1-gallon jugs of milk)
Real-world examples

US car tank ≈ 15 gallons (57 L). 1 US gallon of milk is a common grocery size (3.79 L). US paint often sold by the gallon.

What is the Cubic Foot?

The cubic foot equals approximately 28.317 liters (or exactly 1,728 cubic inches) and is the American standard volume unit for HVAC capacity, natural-gas billing, refrigerator interior volume, and bulk material like concrete or mulch. American gas utilities measure delivered gas in 'CCF' (hundred cubic feet) or 'MCF' (thousand cubic feet), even when the customer thinks in terms of monthly bills. Refrigerators are advertised by their interior cubic-foot capacity (typical home unit: 18–25 ft³). Air-conditioning systems are rated in CFM (cubic feet per minute) airflow. Concrete is sometimes priced by the cubic yard (27 ft³), and mulch and topsoil are often sold by cubic foot bags. The cubic foot relates to the cubic yard (27 ft³ = 1 yd³), the cubic inch (1,728 in³ = 1 ft³), the cubic meter (1 ft³ ≈ 0.0283 m³), and the gallon (1 ft³ ≈ 7.481 US gal).

  • US air-conditioning and ventilation flow (CFM)
  • US natural gas consumption
  • Refrigerator and freezer capacity in the US
Real-world examples

A typical US fridge is 20 cu ft (566 L). US HVAC flow rated in CFM. US residential gas billed per 100 cu ft (CCF).

Learn About Both Units

🧪 Reference

What is the US Gallon?

Read the unit page →
🧪 Reference

What is the Cubic Foot?

Read the unit page →

US Gallon to Cubic Foot FAQ

5 questions
How many cubic feet in a us gallon?
One us gallon equals 0.133681 cubic feet.
How do I convert US gallons to cubic feet?
Multiply the us gallon value by 0.133681 to get the equivalent in cubic feet.
What is 100 US gallons in cubic feet?
100 US gallons equals 13.368056 cubic feet.
Is a us gallon bigger than a cubic foot?
No. 1 us gallon equals 0.133681 cubic feet, so one us gallon is smaller.
How to convert US gallons to cubic feet without a calculator?
Multiply by 0.13 for a quick estimate; use a calculator for precise results.

Related Volume Conversions

Full comparison →

Conversions From Other Categories