How to convert UK gallons to litres
litres = UK gallons × 4.54609 · litres = US gallons × 3.78541
For example, 10 UK gallons is 10 × 4.54609 = 45.46 litres.
UK gallons to litres conversion table
| UK gallons (gal) | Litres (L) |
|---|---|
| 0.5 | 2.27 |
| 1 | 4.55 |
| 2 | 9.09 |
| 3 | 13.64 |
| 4 | 18.18 |
| 5 | 22.73 |
| 6 | 27.28 |
| 8 | 36.37 |
| 10 | 45.46 |
| 12 | 54.55 |
| 15 | 68.19 |
| 20 | 90.92 |
| 25 | 113.65 |
| 50 | 227.3 |
| 100 | 454.61 |
Why it matters for fuel
Petrol and diesel are sold by the litre in the UK, but fuel economy is measured in miles per imperial gallon. At 174.5p a litre, a UK gallon of petrol costs about £7.93. Use the fuel cost calculator to work out what a trip costs, and the MPG calculator to measure your real economy.
Sources
Rates and rules last checked 15 October 2026. These figures are a guide. For a decision that matters, confirm with the official source.