Convert Gallons (US) to Cubic Inches
Gallon (US) (gal) to Cubic Inch (in³) unit conversion — enter any value below to get an instant result, or use the table for common values.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 gal = 231 in³
1 Gallon (US) = 231 Cubic Inches
1 Cubic Inch = 0.0043290043 Gallons (US)
1 gal in every supported unit
Conversion chart: Gallon (US) to Cubic Inches
Conversion table
| Gallon (US) (gal) | Cubic Inch (in³) |
|---|---|
| 0.01 gal | 2.31 in³ |
| 0.1 gal | 23.1 in³ |
| 1 gal | 231 in³ |
| 2 gal | 462 in³ |
| 3 gal | 693 in³ |
| 5 gal | 1155 in³ |
| 10 gal | 2310 in³ |
| 20 gal | 4620 in³ |
| 50 gal | 11550 in³ |
| 100 gal | 23100 in³ |
| 1000 gal | 231000 in³ |
Gallon (US) (gal)
Definition: A US customary unit equal to 4 US quarts, or exactly 3.785411784 liters.
History: Based on the old English wine gallon (231 cubic inches), which the US formally adopted as its liquid gallon standard in the 19th century. Britain instead adopted a larger imperial gallon (about 4.546 L) in 1824, so the US gallon and UK gallon have never been the same size — a common source of confusion when comparing fuel economy or recipe figures across countries.
Current use: The standard unit for fuel prices, milk jugs, and paint or motor oil containers throughout the United States.
Cubic Inch (in³)
Definition: The volume of a cube one inch on each side, equal to exactly 0.016387064 liters.
History: Derived the same way as the cubic foot, as a geometric cube of the inch; it became especially associated with mechanical engineering once precision manufacturing required small-volume measurements.
Current use: Historically the standard unit for automobile engine displacement in the US (e.g. a "350 cubic-inch" V8) before most manufacturers switched to liters, and still used for small mechanical component volumes.
Supported Units
| Unit | Symbol | In Liters |
|---|---|---|
| Milliliter | mL | 0.001 L |
| Liter | L | 1 L |
| Cubic Meter | m³ | 1000 L |
| Cubic Foot | ft³ | 28.316847 L |
| Cubic Inch | in³ | 0.016387064 L |
| Fluid Ounce (US) | fl oz | 0.02957353 L |
| Cup (US) | cup | 0.23658824 L |
| Pint (US) | pt | 0.47317647 L |
| Quart (US) | qt | 0.94635295 L |
| Gallon (US) | gal | 3.7854118 L |
About These Parameters
- Value
- The number you want to convert, expressed in the "From" unit. Accepts decimals.
- From Unit
- The unit your input value is currently measured in.
- To Unit
- The unit you want the result converted into. Use the swap button to flip From and To instantly.
How Volume Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to the liter. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For Gallon (US) → Cubic Inch: multiply by 231. For example, 1 gal × 231 = 231 in³.
US Gallons vs. UK Imperial Gallons
This converter uses US customary volume units exclusively (fluid ounce, cup, pint, quart, gallon), which are not the same size as their UK imperial counterparts. A US gallon is exactly 3.785411784 liters, while a UK imperial gallon is about 4.546 liters — roughly 20% larger. Both systems trace back to old English measures, but the US kept the older wine-gallon standard after 1776 while Britain redefined its units in 1824. This mismatch is a common source of confusion when comparing fuel economy or recipe measurements between the US and UK.
Metric vs. US Customary Volume
The metric units on this page (milliliter, liter, cubic meter) all scale by powers of ten, so converting between them is just moving a decimal point. US customary units (fluid ounce, cup, pint, quart, gallon) use irregular multiples — 8 fluid ounces to a cup, 2 cups to a pint, 2 pints to a quart, 4 quarts to a gallon — inherited from centuries-old English liquid-measure tradition rather than a decimal system.
Volume in the Kitchen
Cups, pints, and quarts are primarily cooking and baking units in the United States — most other countries measure recipe ingredients by weight (grams) instead, which is more precise because ingredients like flour can pack differently depending on how they're scooped. When following a recipe written in cups or fluid ounces, converting to milliliters first can help if you're using a metric kitchen scale or measuring jug.
Example
1 gal equals 231 in³. For scale, that's about 3.79× a standard 1-liter water bottle (1 L, or 0.26417205 gal).
Frequently Asked Questions
How many Cubic Inches are in 1 Gallon (US)?
1 Gallon (US) (gal) equals exactly 231 Cubic Inches (in³).
Why is a US gallon smaller than a UK gallon?
The US kept the older English wine gallon (231 cubic inches, about 3.785 L) after independence, while the UK redefined its gallon in 1824 based on the volume of 10 pounds of water (about 4.546 L) — the two countries never reconciled the difference, so today "gallon" means two different volumes depending on where you are.
How many milliliters are in a US cup?
One US cup equals exactly 236.5882365 milliliters, though many recipes and kitchen tools round this to 240 mL for simplicity.
Is a cubic centimeter the same as a milliliter?
Yes — one cubic centimeter (cm³ or cc) is exactly equal to one milliliter by definition, which is why medical dosing is often labeled in either unit interchangeably.