Convert US gallons to Cubic inches
1 US gallon is 231 in³. One US gallon is exactly 231 cubic inches.
One US gallon is 231 cubic inches. To convert US gallons to cubic inches, multiply by 231; to go the other way, divide by 231 or multiply by 0.0043290043. The factor is exact rather than rounded: it follows from NIST Handbook 130. Exactly 231 cubic inches.
Factor checked against the defining standard · How we check
- US gallons × 231
1 * 231231 in³
1 US gallon in every volume unit
| Unit | Value | Exact factor |
|---|---|---|
| US teaspoons | 768 tsp | × 768 |
| US tablespoons | 256 tbsp | × 256 |
| US fluid ounces | 128 fl oz | × 128 |
| US cups | 16 cup | × 16 |
| US pints | 8 pt | × 8 |
| US quarts | 4 qt | × 4 |
| US gallons (as entered) | 1 gal | — |
| milliliters | 3,785.411784 ml | × 3,785.411784 |
| liters | 3.785411784 L | × 3.785411784 |
| imperial gallons | 0.8326741846 gal (UK) | × 0.832674184629 |
| imperial quarts | 3.330696739 qt (UK) | × 3.33069673852 |
| imperial pints | 6.661393477 pt (UK) | × 6.66139347703 |
| imperial fluid ounces | 133.2278695 fl oz (UK) | × 133.227869541 |
| imperial gills | 26.64557391 gi (UK) | × 26.6455739081 |
| cubic millimetres | 3,785,411.784 mm³ | × 3,785,411.784 |
| cubic centimetres | 3,785.411784 cm³ | × 3,785.411784 |
| cubic inches | 231 in³ | × 231 |
| cubic feet | 0.1336805556 ft³ | × 0.133680555556 |
| cubic yards | 0.004951131687 yd³ | × 0.00495113168724 |
| cubic metres | 0.003785411784 m³ | × 0.003785411784 |
Factors are entered by hand from NIST Handbook 130 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert US gallons to cubic inches? The converter and the working
- 1.Take the measurement in US gallons.
- 2.Multiply by 231 — that is how many cubic inches fit in one US gallon.
- 3.To go back the other way, divide by 231, or multiply by 0.0043290043.
Worked example: 25 US gallons to cubic inches
- Formula
- gal × 231 = in³
- Arithmetic
- 25 × 231 = 5,775 in³
- Answer
- 25 gal = 5,775 in³
The factor is exact, so this figure is exact too — only the display is rounded.
US gallons to cubic inches conversion table
| US gallons | Cubic inches |
|---|---|
| 1 gal | 231 in³ |
| 2 gal | 462 in³ |
| 3 gal | 693 in³ |
| 4 gal | 924 in³ |
| 5 gal | 1,155 in³ |
| 6 gal | 1,386 in³ |
| 7 gal | 1,617 in³ |
| 8 gal | 1,848 in³ |
| 9 gal | 2,079 in³ |
| 10 gal | 2,310 in³ |
| 12 gal | 2,772 in³ |
| 15 gal | 3,465 in³ |
| 20 gal | 4,620 in³ |
| 25 gal | 5,775 in³ |
| 50 gal | 11,550 in³ |
| 100 gal | 23,100 in³ |
| 200 gal | 46,200 in³ |
| 300 gal | 69,300 in³ |
| 500 gal | 115,500 in³ |
| 1000 gal | 231,000 in³ |
| 2000 gal | 462,000 in³ |
| 5000 gal | 1,155,000 in³ |
| 10000 gal | 2,310,000 in³ |
What is a US gallon?
Exactly 231 cubic inches. The imperial gallon is 4.546 liters, so US and UK fuel economy figures are not comparable.
What is a cubic inch?
Exactly 16.387064 millilitres, since the inch is exactly 25.4 mm. American engine displacement was quoted in it until the 1980s — a 350 small block is 5.7 litres.
How many cubic inches are in a US gallon?
One US gallon is 231 cubic inches, exactly. Going the other way, one cubic inch is 0.0043290043 US gallons. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every volume unit here
The whole group — 20 units with their symbols and the size of each one in liters — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a US gallon.
Cite this page
- APA
- Rule Calculator. (2026). Convert US gallons to cubic inches. Rule Calculator. https://rulecalculators.com/convert/gallon-to-cubic-inch
- MLA
- "Convert US gallons to cubic inches." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/gallon-to-cubic-inch.
- Chicago
- Rule Calculator. "Convert US gallons to cubic inches." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/gallon-to-cubic-inch.
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Questions people actually ask
- How many cubic inches are in a US gallon?
- 231. Exactly 16.387064 millilitres, since the inch is exactly 25.4 mm. American engine displacement was quoted in it until the 1980s — a 350 small block is 5.7 litres.
- How do I convert cubic inches back to US gallons?
- Divide by 231, or multiply by 0.0043290043 — they are the same operation.
Other volume conversions
Cubic inches to US gallons — the same conversion the other way.