Convert US Gallon to Cubic Inch
1 us gallon = 231 cubic inch (in³). For example, 10 us gallon = 2,310 cubic inch and 100 us gallon = 23,100 cubic inch. Type any value below to convert us gallon to cubic inch both ways — it runs entirely in your browser.
Quick answer: US Gallon to Cubic Inch
1 US Gallon = 231 Cubic Inch (gal → in³). To convert us gallon to cubic inch, multiply by 231. To convert cubic inch to us gallon, multiply by 0.004329004. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common us gallon-to-cubic inch questions.
How to convert US Gallon to Cubic Inch
To convert us gallon to cubic inch, multiply the number of us gallon by the conversion factor 231, because 1 gal = 231 in³. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 in³ = 0.004329004 gal, so you divide by 231 (or multiply by 0.004329004) to turn cubic inch back into us gallon.
in³ = gal × 231 ·
gal = in³ × 0.004329004
- Write down the value you want to convert, in us gallon.
- Multiply it by 231.
- The result is the same area/length/quantity expressed in cubic inch.
US Gallon to Cubic Inch — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 us gallon is 1,155 cubic inch because 5 gal × 231 = 1,155 in³.
| US Gallon | Calculation | Cubic Inch |
|---|---|---|
| 1 gal | 1 gal × 231 = 231 in³ | 231 in³ |
| 2 gal | 2 gal × 231 = 462 in³ | 462 in³ |
| 3 gal | 3 gal × 231 = 693 in³ | 693 in³ |
| 5 gal | 5 gal × 231 = 1,155 in³ | 1,155 in³ |
| 7 gal | 7 gal × 231 = 1,617 in³ | 1,617 in³ |
| 10 gal | 10 gal × 231 = 2,310 in³ | 2,310 in³ |
| 12 gal | 12 gal × 231 = 2,772 in³ | 2,772 in³ |
| 15 gal | 15 gal × 231 = 3,465 in³ | 3,465 in³ |
| 20 gal | 20 gal × 231 = 4,620 in³ | 4,620 in³ |
| 25 gal | 25 gal × 231 = 5,775 in³ | 5,775 in³ |
| 50 gal | 50 gal × 231 = 11,550 in³ | 11,550 in³ |
| 100 gal | 100 gal × 231 = 23,100 in³ | 23,100 in³ |
Common US Gallon to Cubic Inch conversions
These are the us gallon-to-cubic inch values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 us gallon = 231 cubic inch
- 2 us gallon = 462 cubic inch
- 2.5 us gallon = 577.5 cubic inch
- 3 us gallon = 693 cubic inch
- 4 us gallon = 924 cubic inch
- 5 us gallon = 1,155 cubic inch
- 6 us gallon = 1,386 cubic inch
- 7 us gallon = 1,617 cubic inch
- 8 us gallon = 1,848 cubic inch
- 9 us gallon = 2,079 cubic inch
- 10 us gallon = 2,310 cubic inch
- 12 us gallon = 2,772 cubic inch
- 15 us gallon = 3,465 cubic inch
- 20 us gallon = 4,620 cubic inch
- 25 us gallon = 5,775 cubic inch
- 30 us gallon = 6,930 cubic inch
- 50 us gallon = 11,550 cubic inch
- 75 us gallon = 17,325 cubic inch
- 100 us gallon = 23,100 cubic inch
- 200 us gallon = 46,200 cubic inch
- 500 us gallon = 115,500 cubic inch
- 1000 us gallon = 231,000 cubic inch
US Gallon to Cubic Inch conversion chart (both directions)
The chart below converts us gallon to cubic inch and cubic inch to us gallon side by side, so it works whichever way you need. 1 us gallon = 231 cubic inch, and 1 cubic inch = 0.004329004 us gallon.
| US Gallon → Cubic Inch | Cubic Inch → US Gallon |
|---|---|
| 0.25 gal = 57.75 in³ | 0.25 in³ = 0.001082251 gal |
| 0.5 gal = 115.5 in³ | 0.5 in³ = 0.002164502 gal |
| 1 gal = 231 in³ | 1 in³ = 0.004329004 gal |
| 2 gal = 462 in³ | 2 in³ = 0.008658009 gal |
| 3 gal = 693 in³ | 3 in³ = 0.01298701 gal |
| 4 gal = 924 in³ | 4 in³ = 0.01731602 gal |
| 5 gal = 1,155 in³ | 5 in³ = 0.02164502 gal |
| 6 gal = 1,386 in³ | 6 in³ = 0.02597403 gal |
| 7 gal = 1,617 in³ | 7 in³ = 0.03030303 gal |
| 8 gal = 1,848 in³ | 8 in³ = 0.03463203 gal |
| 9 gal = 2,079 in³ | 9 in³ = 0.03896104 gal |
| 10 gal = 2,310 in³ | 10 in³ = 0.04329004 gal |
| 12 gal = 2,772 in³ | 12 in³ = 0.05194805 gal |
| 15 gal = 3,465 in³ | 15 in³ = 0.06493506 gal |
| 20 gal = 4,620 in³ | 20 in³ = 0.08658009 gal |
| 25 gal = 5,775 in³ | 25 in³ = 0.1082251 gal |
| 30 gal = 6,930 in³ | 30 in³ = 0.1298701 gal |
| 40 gal = 9,240 in³ | 40 in³ = 0.1731602 gal |
| 50 gal = 11,550 in³ | 50 in³ = 0.2164502 gal |
| 75 gal = 17,325 in³ | 75 in³ = 0.3246753 gal |
| 100 gal = 23,100 in³ | 100 in³ = 0.4329004 gal |
| 150 gal = 34,650 in³ | 150 in³ = 0.6493506 gal |
| 200 gal = 46,200 in³ | 200 in³ = 0.8658009 gal |
| 250 gal = 57,750 in³ | 250 in³ = 1.082251 gal |
| 500 gal = 115,500 in³ | 500 in³ = 2.164502 gal |
| 1000 gal = 231,000 in³ | 1000 in³ = 4.329004 gal |
US Gallon vs Cubic Inch: which is bigger?
A us gallon is the larger unit: one us gallon equals 231 cubic inchs. Put another way, you need 231 cubic inchs to make a single us gallon.
What is a US Gallon? History, origin and usage
The everyday American gallon (written simply gal) is the very same US liquid gallon, inherited from the Queen Anne wine gallon of 231 cubic inches; the word gallon itself comes from the Old Northern French galon, a measure for liquids. The US locked this value in when it set its weights and measures in the 1830s.
This is the gallon Americans meet at the petrol pump, the supermarket milk aisle and the hardware-store paint shelf. It underlies the familiar miles-per-gallon figure used to compare car fuel economy in the United States.
Because Britain switched to the larger imperial gallon in 1824, a US gallon holds about a fifth less than a UK gallon, so a car rated 40 mpg in the US is actually thirstier than 40 mpg quoted in imperial gallons. The two systems share a name but not a size.
What is a Cubic Inch? History, origin and usage
The cubic inch is a US customary and imperial unit, the volume of a cube one inch on each side, descended from the medieval English inch. It became fixed once the inch was tied to the metric system, the inch being defined as exactly 25.4 millimetres in 1959.
The cubic inch is best known in the United States as the historic measure of engine displacement, as in a 350 cubic-inch V8, before metric litres took over on most spec sheets. It also appears in some American manufacturing, machining and packaging contexts.
The US liquid gallon is defined as exactly 231 cubic inches, a figure inherited from the old Queen Anne wine gallon. American muscle-car culture still celebrates classic engines by their cubic-inch displacement, such as the 426 and 454.
Convert 1 US Gallon to other units
It can help to see a us gallon next to the other units it is commonly compared with. One us gallon (gal) is equal to:
| 1 US Gallon equals | Unit |
|---|---|
| 3,785.412 mL | Millilitre |
| 378.5412 cL | Centilitre |
| 3.785412 L | Litre |
| 0.003785412 m³ | Cubic Metre |
| 3,785.412 cm³ | Cubic Centimetre |
| 231 in³ | Cubic Inch |
| 0.1336806 ft³ | Cubic Foot |
| 1 US gal | US Gallon |
| 4 US qt | US Quart |
| 4 qt | US Quart |
| 8 US pt | US Pint |
| 8 pt | US Pint |
| 128 US fl oz | US Fluid Ounce |
| 128 fl oz | US Fluid Ounce |
| 133.2279 imp fl oz | Imperial Fluid Ounce |
| 256 tbsp | US Tablespoon |
| 768 tsp | US Teaspoon |
| 32 gi | US Gill |
| 0.1074209 bu | US Bushel |
| 0.02380952 bbl | Oil Barrel |
| 3,785,412 µL | Microlitre |
| 16 US cup | US Cup |
| 128 US fl oz | US Fluid Ounce |
Convert 1 Cubic Inch to other units
One cubic inch (in³) is equal to:
| 1 Cubic Inch equals | Unit |
|---|---|
| 16.38706 mL | Millilitre |
| 1.638706 cL | Centilitre |
| 0.01638706 L | Litre |
| 0.00001638706 m³ | Cubic Metre |
| 16.38706 cm³ | Cubic Centimetre |
| 0.0005787037 ft³ | Cubic Foot |
| 0.004329004 US gal | US Gallon |
| 0.004329004 gal | US Gallon |
| 0.01731602 US qt | US Quart |
| 0.01731602 qt | US Quart |
| 0.03463203 US pt | US Pint |
| 0.03463203 pt | US Pint |
| 0.5541126 US fl oz | US Fluid Ounce |
| 0.5541126 fl oz | US Fluid Ounce |
| 0.576744 imp fl oz | Imperial Fluid Ounce |
| 1.108225 tbsp | US Tablespoon |
| 3.324675 tsp | US Teaspoon |
| 0.1385281 gi | US Gill |
| 0.0004650254 bu | US Bushel |
| 0.0001030715 bbl | Oil Barrel |
| 16,387.06 µL | Microlitre |
| 0.06926407 US cup | US Cup |
| 0.5541126 US fl oz | US Fluid Ounce |
Tips for converting US Gallon to Cubic Inch
- To go from us gallon to cubic inch, multiply by 231; to go back, divide by 231 (or multiply by 0.004329004).
- For a quick mental estimate, remember that 1 us gallon ≈ 231 cubic inch, so 10 us gallon ≈ 2,310 cubic inch.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this US Gallon to Cubic Inch converter
Type a number into the US Gallon field and the equivalent in Cubic Inch appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Cubic Inch field to convert the other way (cubic inch to us gallon). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 gal = 231 in³), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for us gallon-to-cubic inch conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- NIST Special Publication 811 — Guide for the Use of the SI — publishes the exact metric equivalents of the customary units. The inch, foot, yard and mile are defined exactly in metres by the 1959 international yard-and-pound agreement, so every imperial figure on this page is exact, not rounded.
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
Watch the system: a <strong>US</strong> gallon, quart, pint and fluid ounce are <strong>not</strong> the same size as the <strong>imperial (UK)</strong> ones — a US gallon is 3.785 L while an imperial gallon is 4.546 L, and a US fluid ounce (29.57 mL) is slightly larger than an imperial fluid ounce (28.41 mL). The units on this page are labelled US or Imperial so the result is unambiguous.
Frequently asked questions
- How many cubic inch are in 1 us gallon?
- 1 us gallon = 231 cubic inch (in³). To convert any number of us gallon to cubic inch, multiply by 231.
- How do I convert us gallon to cubic inch?
- Multiply the number of us gallon by 231. For example, 10 us gallon = 10 × 231 = 2,310 cubic inch, and 25 us gallon = 5,775 cubic inch.
- How many us gallon are in 1 cubic inch?
- 1 cubic inch = 0.004329004 us gallon. So to convert cubic inch back to us gallon, multiply by 0.004329004.
- What is the formula to convert us gallon to cubic inch?
- cubic inch = us gallon × 231. The reverse formula is us gallon = cubic inch × 0.004329004.
- How much is 100 us gallon in cubic inch?
- 100 us gallon = 23,100 cubic inch. (And 1000 us gallon = 231,000 cubic inch.)
- Which is bigger, a us gallon or a cubic inch?
- A us gallon is larger: 1 us gallon = 231 cubic inch.
- Is this us gallon to cubic inch converter accurate?
- Yes — every value is computed from the exact 231 in³ per gal factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert cubic inch to us gallon too?
- Yes. The converter works both ways — enter a value in either field. 1 cubic inch = 0.004329004 us gallon.