Convert Cubic Inch to US Gallon
Convert cubic inches to us gallons instantly. 1 cubic inch = 0.0043290043 us gallon — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Gallon to Cubic Inch converter for the reverse conversion.
Units explained
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
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 to US Gallon conversion formula
The relationship between cubic inches and us gallons:
To convert cubic inches to us gallons, multiply the value in cubic inches by 0.0043290043. To reverse, multiply us gallons by 231.
How to use this converter
Type a value into the calculator. The result in us gallons updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the US Gallon to Cubic Inch converter for the reverse direction.
Step-by-step: convert cubic inches to us gallons
- Write down the value in cubic inches (in³).
- Multiply that value by the factor 0.0043290043.
- The product is the equivalent value in us gallons (gal).
- To reverse, multiply the us gallon value by 231.
Worked examples
Example 1 — Convert 1 in³ to gal:
1 × 0.0043290043 = 0.0043290043 gal
Example 2 — Convert 100 in³ to gal:
100 × 0.0043290043 = 0.4329004329 gal
Real-world example — Plastic film and laminate thickness
A 500-cubic inch sheet is a typical spec for ID-card laminates and film overlays. Converting to us gallons aligns the value with the unit most CAD systems and material datasheets prefer.
500 in³ × 0.0043290043 = 2.1645021645 gal
Real-world example — Packaging gauge
A 4-cubic inch plastic bag thickness is a common spec for grocery and freezer bags. Converting from cubic inches to us gallons is what packaging buyers do whenever they bridge US and metric supplier quotes.
4 in³ × 0.0043290043 = 0.0173160173 gal
Cubic Inch to US Gallon conversion table
Standard reference values for converting cubic inches to us gallons:
| Cubic Inch [in³] | US Gallon [gal] |
|---|---|
| 0.01 | 4.329004e-5 |
| 0.1 | 0.0004329004 |
| 1 | 0.0043290043 |
| 2 | 0.0086580087 |
| 3 | 0.012987013 |
| 4 | 0.0173160173 |
| 5 | 0.0216450216 |
| 10 | 0.0432900433 |
| 20 | 0.0865800866 |
| 30 | 0.1298701299 |
| 40 | 0.1731601732 |
| 50 | 0.2164502165 |
| 100 | 0.4329004329 |
| 500 | 2.1645021645 |
| 1000 | 4.329004329 |
Frequently asked questions
How many us gallons is 1 cubic inch?
How do I convert cubic inches to us gallons?
How do I convert us gallons back to cubic inches?
How many us gallons is 100 cubic inches?
Popular volume unit conversions
Convert Cubic Inch to other volume units
Show all Cubic Inch conversions
Metric / SI (8 units)
US Customary (Liquid) (8 units)
Imperial (UK) (4 units)
Cubic (length-derived) (2 units)
Cooking / Culinary (3 units)
Sources & references
Conversion factor (1 in³ = 0.0043290043 gal) 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 Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.