Cubic metric volume unit.
Cubic Decimeters to Gallons Converter — dm3 to gal
Convert Cubic Decimeter (dm3) to Gallon (gal) using the exact conversion factor (1 cubic decimeter = 0.2641720524 gallon). See the formula, worked examples, conversion table, history, and common uses.
Cubic Decimeters to Gallons converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
A US liquid gallon is exactly 3.785411784 liters.
Result = input x 0.001 / 0.003785411784.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Cubic Decimeters to Gallons
Cubic Decimeter and Gallon appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Specifically: Cubic metric volume unit, and a US liquid gallon is exactly 3.785411784 liters.
Formula
gallons = cubic decimeters × 0.264172052358
This factor comes from each unit's defined relationship to the category's base unit: 1 cubic decimeter equals 0.001 base units, and 1 gallon equals 0.003785411784 base units, so dividing one by the other gives the direct cubic decimeter-to-gallon factor of 0.264172052358.
Simple example
1 dm3 × 0.2641720524 = 0.2641720524 gal
1 cubic decimeter = 0.2641720524 gallons.
Real-world example
10 dm3 × 0.2641720524 = 2.641720524 gal
10 cubic decimeters = 2.641720524 gallons.
Conversion table
| Cubic Decimeter (dm3) | Gallon (gal) |
|---|---|
| 1 dm3 | 0.2641720524 gal |
| 5 dm3 | 1.320860262 gal |
| 10 dm3 | 2.641720524 gal |
| 25 dm3 | 6.604301309 gal |
| 50 dm3 | 13.20860262 gal |
| 100 dm3 | 26.41720524 gal |
Reverse conversion: Gallon to Cubic Decimeter
0.2641720524 gal × 3.785411784 = 1 dm3
0.2641720524 gallons = 1 cubic decimeters.
cubic decimeters = gallons × 3.785411784
For a page dedicated to this direction, see Gallon to Cubic Decimeter.
Understanding the Cubic Decimeter (dm3)
Cubic metric volume unit.
Understanding the Gallon
Gallon (gal) measures volume. The US liquid gallon is defined as exactly 231 cubic inches, equal to 3.785411784 liters. It is classified as a US customary unit.
Where it's used: United States (fuel, beverage, and liquid measurement)
US gallon vs. imperial gallon. The US liquid gallon (3.785411784 L) and the British imperial gallon (4.54609 L) are different units with the same name; always confirm which one a source is using.
Uses of the Gallon today
- Fuel pump and vehicle fuel-economy measurement in the US
- Beverage and liquid product packaging in the US
- Cooking and recipe measurement in US customary units
History of the Gallon
The US gallon descends from the English wine gallon of 231 cubic inches, a standard used for measuring wine in medieval and early modern England, which the American colonies inherited and retained even after England moved to a different imperial gallon in 1824.
England's 1824 Weights and Measures Act replaced the old wine gallon with a new imperial gallon (based on 10 pounds of water), but the US kept the older 231-cubic-inch definition — which is why the US gallon (3.785 L) and the imperial gallon (4.546 L) differ by about 20% today.
Historical origin. Gallon was not the invention of a single named person; it developed through the process described above.
Gallon — sources
- NIST Handbook 44, Appendix C — General tables of units of measurement, including the US gallon definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many gallons are in 1 cubic decimeter?
1 cubic decimeter equals 0.2641720524 gallons, using the exact defined conversion factor rather than an estimate.
How do I convert cubic decimeter to gallon?
Multiply the cubic decimeter value by 0.2641720524. The converter above does this instantly to whatever precision you set.
How do I convert gallon back to cubic decimeter?
Use the reverse factor: 1 gallon equals 3.785411784 cubic decimeters. You can also use the swap control in the converter above to flip the direction instantly.
What is a cubic decimeter?
Cubic Decimeter (dm3) is a unit of volume.
What is a gallon?
Gallon (gal) measures volume. The US liquid gallon is defined as exactly 231 cubic inches, equal to 3.785411784 liters. It is classified as a US customary unit.
Is the cubic decimeter to gallon conversion exact?
Yes. The US liquid gallon is defined as exactly 231 cubic inches, equal to 3.785411784 liters. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between us gallon vs. imperial gallon?
The US liquid gallon (3.785411784 L) and the British imperial gallon (4.54609 L) are different units with the same name; always confirm which one a source is using.