UK Gallons to Liters Converter
Convert imperial gallons to liters — multiply by 4.546. Results update as you type; exact factors shown.
One imperial gallon is 4.5461 liters — see the exact factor, not a rounded rule of thumb.
How the uk gallons to liters converter works
Volumes convert through the liter (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.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common volume conversions
| From | To | Units |
|---|---|---|
| 1 imp gal | 4.5461 L | imperial gallon to liters |
| 2 imp gal | 9.0922 L | imperial gallons to liters |
| 5 imp gal | 22.7305 L | imperial gallons to liters |
| 10 imp gal | 45.4609 L | imperial gallons to liters |
| 11 imp gal | 50.007 L | imperial gallons to liters |
| 15 imp gal | 68.1914 L | imperial gallons to liters |
| 20 imp gal | 90.9218 L | imperial gallons to liters |
| 25 imp gal | 113.6523 L | imperial gallons to liters |
| 30 imp gal | 136.3827 L | imperial gallons to liters |
| 50 imp gal | 227.3045 L | imperial gallons to liters |
| 100 imp gal | 454.609 L | imperial gallons to liters |
| 200 imp gal | 909.218 L | imperial gallons to liters |
Units in this converter and their exact factors
| Unit | Symbol | One unit in liters |
|---|---|---|
| milliliter | mL | 0.001 liter |
| liter | L | 1 liter |
| cubic meter | m³ | 1,000 liter |
| teaspoon (metric) | tsp | 0.005 liter |
| tablespoon (metric) | tbsp | 0.015 liter |
| cup (metric) | cup | 0.25 liter |
| US fluid ounce | US fl oz | 0.0295735296 liter |
| US cup | US cup | 0.2365882365 liter |
| US pint | US pt | 0.473176473 liter |
| US gallon | US gal | 3.785411784 liter |
| imperial fluid ounce | imp fl oz | 0.0284130625 liter |
| imperial pint | imp pt | 0.56826125 liter |
| imperial gallon | imp gal | 4.54609 liter |
| cubic foot | ft³ | 28.316846592 liter |
FAQFrequently asked questions about volume conversion
How many liters is a UK gallon?
4.54609 liters.
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 Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.