Cubic Inches to Gallons Converter
Type a value in cubic inches to see it in gallons as you type, with the exact formula and a reference chart.
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How this was calculated
- 1 gallon = 231 cubic inches
- 1,000 ÷ 231 = 4.3290043 gal
| in³ | gal |
|---|---|
| 1 in³ | 0.004329 gal |
| 10 in³ | 0.04329 gal |
| 50 in³ | 0.21645 gal |
| 100 in³ | 0.4329 gal |
| 231 in³ | 1 gal |
| 350 in³ | 1.51515 gal |
| 462 in³ | 2 gal |
| 500 in³ | 2.1645 gal |
| 1,000 in³ | 4.329 gal |
| 1,728 in³ | 7.48052 gal |
| 2,000 in³ | 8.65801 gal |
| 5,000 in³ | 21.645 gal |
| 6,480 in³ | 28.0519 gal |
| 10,000 in³ | 43.29 gal |
| gal | in³ |
|---|---|
| 0.005 gal | 1.155 in³ |
| 0.01 gal | 2.31 in³ |
| 0.02 gal | 4.62 in³ |
| 0.05 gal | 11.55 in³ |
| 0.1 gal | 23.1 in³ |
| 0.2 gal | 46.2 in³ |
| 0.5 gal | 115.5 in³ |
| 1 gal | 231 in³ |
| 2 gal | 462 in³ |
| 5 gal | 1,155 in³ |
| 10 gal | 2,310 in³ |
| 20 gal | 4,620 in³ |
How to convert cubic inches to gallons
1 cubic inch = 0.0043290043 gallons. To convert cubic inches to gallons, divide by 231 (or multiply by 0.0043290043). A cubic inch is a 1 in × 1 in × 1 in cube, exactly 16.387064 ml. A US liquid gallon is 231 cubic inches, exactly 3.785411784 L.
Worked examples
- 231 cubic inches = 1 gal (231 ÷ 231)
- 1,000 cubic inches = 4.329 gal (1,000 ÷ 231)
- 6,480 cubic inches = 28.0519 gal (6,480 ÷ 231)
Where this conversion comes up
Cubic inches are used for US engine displacement, boxes and small containers; gallons for gasoline, milk, paint and fish tanks in the US. Tank, aquarium and planter sizes worked out in inches come to cubic inches, and so does engine displacement. The US gallon is defined as exactly 231 in³, so a 30 × 12 × 18 in aquarium (6,480 in³) holds 28.05 gallons before glass and gravel, and a 350 cubic-inch engine displaces 1.52 gallons (5.74 L). A UK imperial gallon is larger, about 277.42 in³, so the same tank holds only 23.36 imperial gallons.
Quick estimate
Divide by 231.
Common mistakes
- Multiplying instead of dividing. A gallon is larger than a cubic inch, so the number of gallons must come out smaller: 231 cubic inches = 1 gal.
- Using the imperial (UK) unit. This page uses US measures. An imperial gallon is 4.546 L (20% more than a US gallon), an imperial pint 568 ml and an imperial fluid ounce 28.41 ml.
- Rounding too early. Keep the full factor until the last step; rounding 0.00433 to 0.0043 first puts large values noticeably off.
Related volume converters: ml to oz, oz to ml, liters to gallons, gallons to liters, liters to quarts, quarts to liters.
Frequently asked questions
How do you convert cubic inches to gallons?
Multiply the cubic inches by 0.0043290043 (or divide by 231). For example, 1,000 cubic inches is 4.329 gallons.
How many gallons are in one cubic inch?
One cubic inch is 0.0043290043 gallons. A cubic inch is a 1 in × 1 in × 1 in cube, exactly 16.387064 ml.
What is 6,480 cubic inches in gallons?
6,480 cubic inches is 28.0519 gallons.
Is there a quick way to estimate cubic inches to gallons?
Divide by 231.