Cubic inches to gallons converter
Type a value in either box, and the answer shows it in the other unit as you type.
- Gallons (gal)
- 0.004329
1 in³ = 0.004329 gal.
Gallons (gal): 0.004329. 1 in³ = 0.004329 gal.
Gallons (gal) by cubic inches (in³)
How to calculate
Converts cubic inches (in³) to gallons (gal) and back, with the exact unit definitions.
Example with the default inputs (Cubic inches (in³) 1): 1 in³ = 0.004329 gal.
Formula: gal = in³ × 0.004329004329 (the same as in³ ÷ 231)
- 1 cubic inch = 0.004329004329 gallons, from the exact definitions in NIST SP 811.
- Cups, ounces, tablespoons, teaspoons, pints, quarts, and gallons are US customary units: 1 US cup is 8 US fluid ounces.
- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up; an answer of 1 billion or more shows at most 15 significant digits.
Worked examples
Each example is checked against the calculator on every build.
- Cubic inches (in³) 1 gives Gallons (gal) 0.004329.Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8
- Cubic inches (in³) 231 gives Gallons (gal) 1.Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8
- Gallons (gal) 1 gives Cubic inches (in³) 231.Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8
Other questions people ask
How many gallons are in a cubic inch?
1 cubic inch is 0.004329 gallons, from the exact unit definitions (NIST SP 811).
How do I convert cubic inches to gallons?
Divide by 231: gal = in³ × 0.004329004329 (the same as in³ ÷ 231). For example, 1 in³ ÷ 231 = 0.004329 gal.
How do I convert gallons back to cubic inches?
Multiply by 231, or type the gallons into the second box and the converter works it out. 1 gallon is 231 cubic inches.
How many cubic inches are in a gallon?
231 exactly: NIST Handbook 44 defines the US gallon as 231 in³, so gallons = in³ ÷ 231, and 1,000 in³ is 4.329004 gal. A cubic inch is 16.387064 mL exactly, (2.54 cm)³.
Is this a US or a UK gallon?
The US liquid gallon, 231 in³ or 3.785411784 L. A UK (imperial) gallon is 4.54609 L, about 277.42 in³, so the same volume is about 17% fewer UK gallons.