UK Gallons to Litres Converter
Convert imperial gallons to litres — multiply by 4.546. Results update as you type; exact factors shown.
One imperial gallon is 4.5461 litres — see the exact factor, not a rounded rule of thumb.
How the uk gallons to litres converter works
Volumes convert through the litre (exactly 1 dm³). The US gallon is exactly 3.785411784 L (231 cubic inches); the imperial gallon is exactly 4.54609 L. A US fluid ounce is 29.5735 mL, an imperial fluid ounce 28.4131 mL; a US pint is 16 US fl oz, an imperial pint 20 imperial fl oz.
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
Common volume conversions
| From | To | Units |
|---|---|---|
| 1 imp gal | 4.5461 L | imperial gallon to litres |
| 2 imp gal | 9.0922 L | imperial gallons to litres |
| 5 imp gal | 22.7305 L | imperial gallons to litres |
| 10 imp gal | 45.4609 L | imperial gallons to litres |
| 11 imp gal | 50.007 L | imperial gallons to litres |
| 15 imp gal | 68.1914 L | imperial gallons to litres |
| 20 imp gal | 90.9218 L | imperial gallons to litres |
| 25 imp gal | 113.6523 L | imperial gallons to litres |
| 30 imp gal | 136.3827 L | imperial gallons to litres |
| 50 imp gal | 227.3045 L | imperial gallons to litres |
| 100 imp gal | 454.609 L | imperial gallons to litres |
| 200 imp gal | 909.218 L | imperial gallons to litres |
Units in this converter and their exact factors
| Unit | Symbol | One unit in litres |
|---|---|---|
| millilitre | mL | 0.001 litre |
| litre | L | 1 litre |
| cubic metre | m³ | 1,000 litre |
| teaspoon (metric) | tsp | 0.005 litre |
| tablespoon (metric) | tbsp | 0.015 litre |
| cup (metric) | cup | 0.25 litre |
| US fluid ounce | US fl oz | 0.0295735296 litre |
| US cup | US cup | 0.2365882365 litre |
| US pint | US pt | 0.473176473 litre |
| US gallon | US gal | 3.785411784 litre |
| imperial fluid ounce | imp fl oz | 0.0284130625 litre |
| imperial pint | imp pt | 0.56826125 litre |
| imperial gallon | imp gal | 4.54609 litre |
| cubic foot | ft³ | 28.316846592 litre |
FAQFrequently asked questions about volume conversion
How many litres is a UK gallon?
4.54609 litres.
Is a UK gallon bigger?
Yes, by about 20% over the US gallon.
How many UK pints in a gallon?
Eight, each 568 ml.
Which gallon does UK fuel economy use?
The imperial one, which is why UK mpg figures look better than US ones for the same car.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.