Conversion
Us Gallons to cubic inches
1 US gal = 231 in³, derived from exact unit definitions.
—
Swap ⇆| US gal | in³ |
|---|---|
| 1 US gal | 231 in³ |
| 5 US gal | 1,155 in³ |
| 10 US gal | 2,310 in³ |
| 55 US gal | 12,705 in³ |
| 100 US gal | 23,100 in³ |
| 275 US gal | 63,525 in³ |
| 500 US gal | 115,500 in³ |
Formula
cubic inches = US gallons × 231FAQ
How many cubic inches in a US gallon?
1 US gal = 231 in³. Multiply your US gallons value by 231.
Is this exact?
Yes — these factors derive from exact definitions: 1 US gallon = 231 cubic inches, 1 imperial gallon = 4.54609 liters, 1 inch = 2.54 cm, 1 barrel = 42 US gallons.
Why do tank specs mix US gallons and cubic inches?
US tank trade uses gallons and inches; engineering drawings and international suppliers use metric or cubic measures. This page bridges them without rounding drift.