Convert Imperial gallons to Cubic inches
1 imperial gallon is 277.42 in³. One imperial gallon is exactly 277.419432792 cubic inches.
One imperial gallon is 277.41943 cubic inches. To convert imperial gallons to cubic inches, multiply by 277.41943; to go the other way, divide by 277.41943 or multiply by 0.0036046501. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Handbook 130.
Factor checked against the defining standard · How we check
- Imperial gallons × 277.41943
1 * 277.41943277.419 in³
1 imperial gallon in every volume unit
| Unit | Value | Exact factor |
|---|---|---|
| US teaspoons | 922.3295428 tsp | × 922.329542788 |
| US tablespoons | 307.4431809 tbsp | × 307.443180929 |
| US fluid ounces | 153.7215905 fl oz | × 153.721590465 |
| US cups | 19.21519881 cup | × 19.2151988081 |
| US pints | 9.607599404 pt | × 9.60759940404 |
| US quarts | 4.803799702 qt | × 4.80379970202 |
| US gallons | 1.200949926 gal | × 1.2009499255 |
| milliliters | 4,546.09 ml | × 4,546.09 |
| liters | 4.54609 L | × 4.54609 |
| imperial gallons (as entered) | 1 gal (UK) | — |
| imperial quarts | 4 qt (UK) | × 4 |
| imperial pints | 8 pt (UK) | × 8 |
| imperial fluid ounces | 160 fl oz (UK) | × 160 |
| imperial gills | 32 gi (UK) | × 32 |
| cubic millimetres | 4,546,090 mm³ | × 4,546,090 |
| cubic centimetres | 4,546.09 cm³ | × 4,546.09 |
| cubic inches | 277.4194328 in³ | × 277.419432792 |
| cubic feet | 0.1605436532 ft³ | × 0.160543653236 |
| cubic yards | 0.005946061231 yd³ | × 0.00594606123096 |
| cubic metres | 0.00454609 m³ | × 0.00454609 |
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 imperial gallons to cubic inches? The converter and the working
- 1.Take the measurement in imperial gallons.
- 2.Multiply by 277.41943 — that is how many cubic inches fit in one imperial gallon.
- 3.To go back the other way, divide by 277.41943, or multiply by 0.0036046501.
Worked example: 25 imperial gallons to cubic inches
- Formula
- gal (UK) × 277.41943 = in³
- Arithmetic
- 25 × 277.41943 = 6,935.49 in³
- Answer
- 25 gal (UK) = 6,935.49 in³
The factor is rounded for display; the figure above is computed from the full value.
Imperial gallons to cubic inches conversion table
| Imperial gallons | Cubic inches |
|---|---|
| 1 gal (UK) | 277.42 in³ |
| 2 gal (UK) | 554.84 in³ |
| 3 gal (UK) | 832.26 in³ |
| 4 gal (UK) | 1,109.68 in³ |
| 5 gal (UK) | 1,387.1 in³ |
| 6 gal (UK) | 1,664.52 in³ |
| 7 gal (UK) | 1,941.94 in³ |
| 8 gal (UK) | 2,219.36 in³ |
| 9 gal (UK) | 2,496.77 in³ |
| 10 gal (UK) | 2,774.19 in³ |
| 12 gal (UK) | 3,329.03 in³ |
| 15 gal (UK) | 4,161.29 in³ |
| 20 gal (UK) | 5,548.39 in³ |
| 25 gal (UK) | 6,935.49 in³ |
| 50 gal (UK) | 13,870.97 in³ |
| 100 gal (UK) | 27,741.94 in³ |
| 200 gal (UK) | 55,483.89 in³ |
| 300 gal (UK) | 83,225.83 in³ |
| 500 gal (UK) | 138,709.72 in³ |
| 1000 gal (UK) | 277,419.43 in³ |
| 2000 gal (UK) | 554,838.87 in³ |
| 5000 gal (UK) | 1,387,097.16 in³ |
| 10000 gal (UK) | 2,774,194.33 in³ |
What is an imperial gallon?
Exactly 4.54609 liters since 1985, and the reason UK and US fuel economy figures cannot be compared: it is 20% larger than the US gallon, so 40 mpg in Britain is about 33 mpg in America on the same car.
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 an imperial gallon?
One imperial gallon is 277.41943 cubic inches. Going the other way, one cubic inch is 0.0036046501 imperial 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 an imperial gallon.
Cite this page
- APA
- Rule Calculator. (2026). Convert Imperial gallons to cubic inches. Rule Calculator. https://rulecalculators.com/convert/imperial-gallon-to-cubic-inch
- MLA
- "Convert Imperial gallons to cubic inches." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/imperial-gallon-to-cubic-inch.
- Chicago
- Rule Calculator. "Convert Imperial gallons to cubic inches." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/imperial-gallon-to-cubic-inch.
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Questions people actually ask
- How many cubic inches are in an imperial gallon?
- 277.41943. 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 imperial gallons?
- Divide by 277.41943, or multiply by 0.0036046501 — they are the same operation.
Other volume conversions
Cubic inches to imperial gallons — the same conversion the other way.