US Gallons to Cubic Inches
Convert us gallons to cubic inches instantly. 1 gal = 231 in³. Includes the exact factor, a conversion table of common values and the definition of both units.
How to convert us gallons to cubic inches
To convert us gallons to cubic inches, multiply by 231. The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.
in³ = gal × 231
US Gallons to Cubic Inches conversion table
The values people look up most often, rounded for reading. Use the calculator above for anything in between.
| US Gallons | Cubic Inches |
|---|---|
| 1 gal | 231 in³ |
| 2 gal | 462 in³ |
| 3 gal | 693 in³ |
| 5 gal | 1,155 in³ |
| 10 gal | 2,310 in³ |
| 20 gal | 4,620 in³ |
| 25 gal | 5,775 in³ |
| 50 gal | 11,550 in³ |
| 100 gal | 23,100 in³ |
| 500 gal | 115,500 in³ |
| 1,000 gal | 231,000 in³ |
What is a us gallon?
Exactly 231 cubic inches — smaller than the imperial gallon.
What is a cubic inch?
Exactly 16.387064 mL. The classic US engine-displacement unit.
The formula
in³ = gal × 231
Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.
How to use the US Gallons to Cubic Inches
- Type the number of us gallons you want to convert.
- Read the result in cubic inches straight away — there is no button to press.
- Check the table below for the values that come up most often, or reverse the conversion with the linked cubic inches to us gallons page.
US Gallons to Cubic Inches — frequently asked questions
How many cubic inches are in a us gallon?
One us gallon equals 231 in³. in³ = gal × 231
What is the formula to convert us gallons to cubic inches?
The formula is in³ = gal × 231. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.
How do I convert cubic inches back to us gallons?
Divide instead of multiplying: one cubic inch is 0.0043290043 gal. The reverse converter is linked in the related tools list.
Is this conversion exact?
Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.
Is this us gallons to cubic inches free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
What people search for
This page answers each of these searches. They are the exact phrases visitors use to find the us gallons to cubic inches.
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About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 15, 2026 · Calculation runs client-side · No data collected · Report an error