Convert Imperial Gallon to Cubic Decimeter
Convert imperial gallons to cubic decimeters instantly. 1 imperial gallon = 4.54609 cubic decimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Cubic Decimeter to Imperial Gallon converter for the reverse conversion.
Units explained
Imperial Gallon
The imperial gallon is defined as exactly 4.54609 liters.
Set by the British Weights and Measures Act of 1824 as the volume of 10 lb of water.
Used for fuel and beverages in the UK and Commonwealth.
UK, 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.
Imperial Gallon to Cubic Decimeter conversion formula
The relationship between imperial gallons and cubic decimeters:
To convert imperial gallons to cubic decimeters, multiply the value in imperial gallons by 4.54609. To reverse, multiply cubic decimeters by 0.2199692483.
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 Imperial Gallon converter for the reverse direction.
Step-by-step: convert imperial gallons to cubic decimeters
- Write down the value in imperial gallons (gal).
- Multiply that value by the factor 4.54609.
- The product is the equivalent value in cubic decimeters (dm³).
- To reverse, multiply the cubic decimeter value by 0.2199692483.
Worked examples
Example 1 — Convert 1 gal to dm³:
1 × 4.54609 = 4.54609 dm³
Example 2 — Convert 100 gal to dm³:
100 × 4.54609 = 454.609 dm³
Real-world example — Ruler-scale measurements
A 30-imperial 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 × 4.54609 = 136.3827 dm³
Real-world example — Hardware-scale dimensions
A 10-imperial gallon fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between imperial gallons and cubic decimeters daily when mixing metric and imperial tools.
10 gal × 4.54609 = 45.4609 dm³
Real-world example — Postcard and small-object dimensions
A postcard is about 5 imperial gallons wide. Converting to cubic decimeters is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 gal × 4.54609 = 22.73045 dm³
Imperial Gallon to Cubic Decimeter conversion table
Standard reference values for converting imperial gallons to cubic decimeters:
| Imperial Gallon [gal] | Cubic Decimeter [dm³] |
|---|---|
| 0.01 | 0.0454609 |
| 0.1 | 0.454609 |
| 1 | 4.54609 |
| 2 | 9.09218 |
| 3 | 13.63827 |
| 4 | 18.18436 |
| 5 | 22.73045 |
| 10 | 45.4609 |
| 20 | 90.9218 |
| 30 | 136.3827 |
| 40 | 181.8436 |
| 50 | 227.3045 |
| 100 | 454.609 |
| 500 | 2273.045 |
| 1000 | 4546.09 |
Frequently asked questions
How many cubic decimeters is 1 imperial gallon?
How do I convert imperial gallons to cubic decimeters?
How do I convert cubic decimeters back to imperial gallons?
How many cubic decimeters is 100 imperial gallons?
Popular volume unit conversions
Convert Imperial Gallon to other volume units
Show all Imperial Gallon conversions
Metric / SI (15 units)
US Customary (Liquid) (15 units)
US Customary (Dry) (5 units)
Imperial (UK) (13 units)
Cubic (length-derived) (4 units)
Cooking / Culinary (5 units)
Sources & references
Conversion factor (1 gal = 4.54609 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.