Gallons to Litres Converter
Convert UK gallons to litres instantly. Free gallon to litre converter for fuel economy and liquid measurements.
Formula
litres = gallons × 4.54609
Common Conversions
Gallons Are Different Sizes (UK vs US)
UK gallon = 4.546 litres. US gallon = 3.785 litres. The UK gallon is about 20% larger - significant when converting fuel prices or bulk liquid measurements. Multiply UK gallons by 4.546 (or US gallons by 3.785) to get litres.
Most US fuel pricing uses US gallons. UK fuel pricing now uses litres exclusively (since 1995); the UK gallon survives mainly in older non-fuel contexts. American brewing recipes often specify 'a gallon of water' meaning US gallon (3.785 L). Always check origin.
Common Gallons to Litres Conversions
| Gallons | UK Litres | US Litres |
|---|---|---|
| 1 gal | 4.546 L | 3.785 L |
| 2 gal | 9.092 L | 7.571 L |
| 3 gal | 13.638 L | 11.356 L |
| 5 gal | 22.730 L | 18.927 L |
| 10 gal | 45.461 L | 37.854 L |
| 15 gal | 68.191 L | 56.781 L |
| 20 gal | 90.922 L | 75.708 L |
| 50 gal | 227.305 L | 189.271 L |
Frequently Asked Questions
Why are UK and US gallons different?
Different historical bases. UK gallon comes from the wine gallon as defined by Queen Anne in 1707, equal to 8 pints of 568 ml. The US adopted a smaller version of the gallon definition (231 cubic inches), which became 3.785 L.
What does '1 gallon' mean in a recipe?
Almost always US gallon (3.785 L) for American recipes, UK gallon (4.546 L) for British recipes. The 20% difference can ruin yields if the wrong assumption is made. American recipe sites and cookbooks default to US gallon.
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