---
title: "Cubic inches to US gallons — in³ to gal converter"
description: "1 cubic inch = 0.004329 US gallons. Convert cubic inches to US gallons with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/cubic-inches-to-gallons/
site: "At One Place"
---

# Cubic inches to US gallons

**1 cubic inch in US gallons: 1 in³ = 0.004329 gal**

gal = in³ × 0.004329004329

To convert cubic inches to US gallons, multiply by 0.004329004329. The table below gives the values people look up most often, and the converter works for any number.

## Cubic inches to US gallons table

*Common cubic inch values converted to US gallons.*

| Cubic inches | US gallons |
| --- | --- |
| 1 in³ | 0.004329 |
| 2 in³ | 0.008658 |
| 3 in³ | 0.012987 |
| 4 in³ | 0.017316 |
| 5 in³ | 0.021645 |
| 10 in³ | 0.04329 |
| 15 in³ | 0.064935 |
| 20 in³ | 0.08658 |
| 25 in³ | 0.10823 |
| 30 in³ | 0.12987 |
| 40 in³ | 0.17316 |
| 50 in³ | 0.21645 |
| 75 in³ | 0.32468 |
| 100 in³ | 0.4329 |
| 250 in³ | 1.082251 |
| 500 in³ | 2.164502 |
| 1,000 in³ | 4.329004 |

## How the conversion works

The relationship is gal = in³ × 0.004329004329. Both units measure volume, so the conversion is a fixed factor that never changes. The figure is exact rather than approximate: since the international yard and pound agreement of 1959, an inch is defined as exactly 25.4 millimetres and a pound as exactly 0.45359237 kilograms, and every other imperial and US customary unit here is derived from those two.

> US gallon: US liquid gallon. The imperial gallon is about 20% larger.

## Common questions

### How many US gallons are in one cubic inch?

One cubic inch equals 0.004329 US gallons. gal = in³ × 0.004329004329.

### How do you convert cubic inches to US gallons?

Use gal = in³ × 0.004329004329. So 10 in³ is 0.04329 gal.

### How many cubic inches are in one US gallon?

One US gallon equals 231 cubic inches, which is the reverse of the conversion above.

### Is there more than one kind of US gallon?

US liquid gallon. The imperial gallon is about 20% larger.

## Related pages

- [US gallons to Cubic inches](https://atoneplace.net/convert/gallons-to-cubic-inches/)
- [Cubic inches to Liters](https://atoneplace.net/convert/cubic-inches-to-liters/)
- [Cubic inches to Milliliters](https://atoneplace.net/convert/cubic-inches-to-ml/)
- [Cubic inches to Cubic meters](https://atoneplace.net/convert/cubic-inches-to-cubic-meters/)
- [Cubic inches to US quarts](https://atoneplace.net/convert/cubic-inches-to-quarts/)
- [Cubic inches to US pints](https://atoneplace.net/convert/cubic-inches-to-pints/)
- [Cubic inches to US cups](https://atoneplace.net/convert/cubic-inches-to-cups/)
- [Cubic inches to US fluid ounces](https://atoneplace.net/convert/cubic-inches-to-fl-oz/)
- [Cubic inches to Tablespoons](https://atoneplace.net/convert/cubic-inches-to-tablespoons/)
- [Cubic inches to Teaspoons](https://atoneplace.net/convert/cubic-inches-to-teaspoons/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)