Convert US Gallon to Cubic Inch (gal (US) → in³)
The US gallon is the standard unit for fuel, milk, and beverages across the United States.
US Gallon to Cubic Inch Conversion Table
10 common values| US Gallon | Cubic Inch |
|---|---|
| 1 gal (US) | 231 in³ |
| 2 gal (US) | 462 in³ |
| 5 gal (US) | 1,155 in³ |
| 10 gal (US) | 2,310 in³ |
| 20 gal (US) | 4,620 in³ |
| 50 gal (US) | 11,550 in³ |
| 100 gal (US) | 23,100 in³ |
| 200 gal (US) | 46,200 in³ |
| 500 gal (US) | 115,500 in³ |
| 1,000 gal (US) | 231,000 in³ |
How to Convert US Gallon to Cubic Inch Manually
Step by StepConverting US gallons to cubic inches is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in US gallonsStart with the number of US gallons (gal (US)) you want to convert.
- 2Multiply by 231The conversion factor from gal (US) to in³ is 231. Multiply your value by this number.
- 3Read the result in cubic inchesThe result is your value in cubic inches (in³).
Formula
Multiply the value in US gallons by 231. For the reverse direction, multiply by 0.004329.
in³ = gal (US) × 231gal (US) = in³ × 0.004329Tips
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 Inch
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)
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 Inch?
The cubic inch equals exactly 16.387064 cubic centimeters and is the traditional American unit for engine displacement and small-volume manufacturing measurements. Classic American muscle cars were famously identified by their cubic-inch engine size: the Ford 'Boss 429' had a 429-cubic-inch (7.0-liter) V8, and the Chevrolet 'Big Block 454' was 7.4 liters. Modern American automakers have transitioned mostly to liter-based naming (e.g., 'Hemi 5.7'), but the cubic inch persists in vintage car culture and aviation engines. It is also used for printer-paper coverage and industrial tolerances. The cubic inch relates to the cubic foot (1,728 in³ = 1 ft³), the cubic centimeter (1 in³ ≈ 16.39 cm³), the milliliter (1 in³ ≈ 16.39 mL), and the US fluid ounce (1 fl oz ≈ 1.805 in³).
- Classic US car engine displacement
- Firearms chamber and cartridge specs
- Some US machining and mould design
350 cu in V8 = 5.7 L engine. 302 cu in Ford V8 = 4.9 L. Modern specs typically give litres.