Cubic Inches to Gallons Calculator
Convert cubic inches (in³) to US gallons (gal) instantly. Essential for engine displacement, tank volume, and fluid calculations.
Volume ConverterLive
Precision:
in³
—
Formula
n in³ ÷ 231 = ? galQuick Values
How to Convert Cubic Inches to US Gallons
gal = in³ ÷ 231 (1 US gallon = 231 cubic inches exactly)→1 US gallon = exactly 231 cubic inches — this is the legal US definition.
→A 350 in³ engine ≈ 1.515 gallons of displacement.
→Used heavily in automotive engine specs (e.g. 454 in³ = ~1.96 gal).
→To reverse: multiply gallons × 231 to get cubic inches.
→Note: 1 Imperial (UK) gallon = 277.42 in³, not 231.
Cubic Inches → US Gallons Reference Table
| Cubic Inches (in³) | US Gallons (gal) |
|---|---|
| 1 | 0.0043 |
| 2 | 0.0087 |
| 5 | 0.0216 |
| 10 | 0.0433 |
| 25 | 0.1082 |
| 50 | 0.2165 |
| 100 | 0.4329 |
| 250 | 1.0823 |
| 500 | 2.1645 |
| 1,000 | 4.329 |
Click any row to load into the calculator.
📦Unit Reference
Cubic Inches
1 in³ = 0.0043 gal
US Gallons
1 gal = 231 in³
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