Convert US Gallon to Cubic Decimeter
Convert us gallons to cubic decimeters instantly. 1 us gallon = 3.785411784 cubic decimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Cubic Decimeter 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 Decimeter
A cubic decimeter is the volume of a cube one decimeter on a side, exactly equal to one liter (0.001 m³).
Derived from the decimeter; in 1964 the CGPM defined the liter as exactly one cubic decimeter.
Common in chemistry and engineering as an exact synonym for the liter.
CGPM, 1964.
US Gallon to Cubic Decimeter conversion formula
The relationship between us gallons and cubic decimeters:
To convert us gallons to cubic decimeters, multiply the value in us gallons by 3.785411784. To reverse, multiply cubic decimeters by 0.2641720524.
How to use this converter
Type a value into the calculator. The result in cubic decimeters 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 Decimeter to US Gallon converter for the reverse direction.
Step-by-step: convert us gallons to cubic decimeters
- Write down the value in us gallons (gal).
- Multiply that value by the factor 3.785411784.
- The product is the equivalent value in cubic decimeters (dm³).
- To reverse, multiply the cubic decimeter value by 0.2641720524.
Worked examples
Example 1 — Convert 1 gal to dm³:
1 × 3.785411784 = 3.785411784 dm³
Example 2 — Convert 100 gal to dm³:
100 × 3.785411784 = 378.5411784 dm³
Real-world example — Ruler-scale measurements
A 30-us gallon school ruler converts cleanly to cubic decimeters — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 gal × 3.785411784 = 113.56235352 dm³
Real-world example — Hardware-scale dimensions
A 10-us gallon fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between us gallons and cubic decimeters daily when mixing metric and imperial tools.
10 gal × 3.785411784 = 37.85411784 dm³
Real-world example — Postcard and small-object dimensions
A postcard is about 5 us gallons wide. Converting to cubic decimeters is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 gal × 3.785411784 = 18.92705892 dm³
US Gallon to Cubic Decimeter conversion table
Standard reference values for converting us gallons to cubic decimeters:
| US Gallon [gal] | Cubic Decimeter [dm³] |
|---|---|
| 0.01 | 0.0378541178 |
| 0.1 | 0.3785411784 |
| 1 | 3.785411784 |
| 2 | 7.570823568 |
| 3 | 11.356235352 |
| 4 | 15.141647136 |
| 5 | 18.92705892 |
| 10 | 37.85411784 |
| 20 | 75.70823568 |
| 30 | 113.56235352 |
| 40 | 151.41647136 |
| 50 | 189.2705892 |
| 100 | 378.5411784 |
| 500 | 1892.705892 |
| 1000 | 3785.411784 |
Frequently asked questions
How many cubic decimeters is 1 us gallon?
How do I convert us gallons to cubic decimeters?
How do I convert cubic decimeters back to us gallons?
How many cubic decimeters 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 = 3.785411784 dm³) 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.