Convert US Gallon to Cubic Inch
Convert us gallons to cubic inches instantly. 1 us gallon = 231 cubic inch — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Cubic Inch to US Gallon converter for the reverse conversion.
Units explained
US Gallon
The US liquid gallon is defined as exactly 231 cubic inches (3.785411784 liters).
Based on the English wine gallon of 231 cubic inches, retained by the US after 1824.
The primary US unit for fuel, milk and large beverage containers.
English wine gallon; US since 1824.
Cubic Inch
A cubic inch is the volume of a cube one inch on a side (16.387 mL).
Derived by cubing the international inch (25.4 mm).
Used for engine displacement and small-part volumes.
1959 yard agreement.
US Gallon to Cubic Inch conversion formula
The relationship between us gallons and cubic inches:
To convert us gallons to cubic inches, multiply the value in us gallons by 231. To reverse, multiply cubic inches by 0.0043290043.
How to use this converter
Type a value into the calculator. The result in cubic inches updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Cubic Inch to US Gallon converter for the reverse direction.
Step-by-step: convert us gallons to cubic inches
- Write down the value in us gallons (gal).
- Multiply that value by the factor 231.
- The product is the equivalent value in cubic inches (in³).
- To reverse, multiply the cubic inch value by 0.0043290043.
Worked examples
Example 1 — Convert 1 gal to in³:
1 × 231 = 231 in³
Example 2 — Convert 100 gal to in³:
100 × 231 = 23100 in³
Real-world example — Adjacent small-scale precision
One us gallon equals 1,000 cubic inches — the standard sub-millimeter precision conversion that materials engineers use whenever they switch between bulk material thickness specs (larger unit) and surface-finish characteristics (smaller unit).
1 gal × 231 = 231 in³
Real-world example — Adjacent metric sub-units
One us gallon equals 1,000 cubic inches. Engineers move between these scales constantly: PCB feature sizes in the larger unit, wire-bond diameters in the smaller.
1 gal × 231 = 231 in³
US Gallon to Cubic Inch conversion table
Standard reference values for converting us gallons to cubic inches:
| US Gallon [gal] | Cubic Inch [in³] |
|---|---|
| 0.01 | 2.31 |
| 0.1 | 23.1 |
| 1 | 231 |
| 2 | 462 |
| 3 | 693 |
| 4 | 924 |
| 5 | 1155 |
| 10 | 2310 |
| 20 | 4620 |
| 30 | 6930 |
| 40 | 9240 |
| 50 | 11550 |
| 100 | 23100 |
| 500 | 115500 |
| 1000 | 231000 |
Frequently asked questions
How many cubic inches is 1 us gallon?
How do I convert us gallons to cubic inches?
How do I convert cubic inches back to us gallons?
How many cubic inches is 100 us gallons?
Popular volume unit conversions
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Metric / SI (15 units)
US Customary (Liquid) (14 units)
US Customary (Dry) (5 units)
Imperial (UK) (14 units)
Cubic (length-derived) (4 units)
Cooking / Culinary (5 units)
Sources & references
Conversion factor (1 gal = 231 in³) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.