UK gallons to liters
L = gal × 4.54609
Exact factor: 1 imperial gallon = 4.54609 dm³.
Convert liters to UK gallons (and imperial gallons to liters)
Two-way liters ↔ UK gallons converter: exact factor (1 imperial gallon = 4.54609 L, Weights and Measures Act 1985), formula, the difference from the US gallon, the imperial pint and real examples (fuel tanks, UK mpg).
Conversion table
| L | gal UK |
|---|---|
| 1 L | 0.22 gal UK |
| 2 L | 0.4399 gal UK |
| 5 L | 1.09985 gal UK |
| 10 L | 2.19969 gal UK |
| 20 L | 4.39938 gal UK |
| 50 L | 10.9985 gal UK |
| 100 L | 21.9969 gal UK |
| 1,000 L | 219.969 gal UK |
| gal UK | L |
|---|---|
| 1 gal UK | 4.54609 L |
| 2 gal UK | 9.09218 L |
| 5 gal UK | 22.7304 L |
| 10 gal UK | 45.4609 L |
| 20 gal UK | 90.9218 L |
| 50 gal UK | 227.305 L |
| 100 gal UK | 454.609 L |
| 1,000 gal UK | 4,546.09 L |
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How does this tool work?
This converter turns liters into British imperial gallons (UK gallons) and UK gallons into liters: type a value in either field and the other updates instantly. It is used to read a British car's fuel economy quoted in miles per gallon, to make sense of a tank or can capacity in the UK, to convert pints and gallons of beer or milk, or to check that a source really means the imperial gallon and not the US one.
The imperial gallon is defined by the UK Weights and Measures Act 1985 as 4.54609 cubic decimetres, exactly 4.54609 L. It replaced the older 1824 definition (the volume of 10 pounds of water). It follows that 1 L ≈ 0.219969 UK gallon.
To convert liters to UK gallons, divide by 4.54609 (or multiply by 0.219969); to convert gallons to liters, multiply by 4.54609. The gallon splits into 4 quarts, 8 pints or 160 imperial fluid ounces, so one pint is 0.56826125 L, that is 568 mL, the size of a British pint of beer.
In your head, count 4.5 L per gallon and add 1%: 10 gal → 45 + 0.45 ≈ 45.5 L (exact value 45.46). The other way, divide liters by 4.5 and take off 1%: 40 L → 8.89 − 0.09 ≈ 8.80 gal (exact value 8.80).
Do not confuse the UK gallon with the US gallon, which is 3.785411784 L: the imperial gallon is about 20% larger (1 UK gal = 1.20095 US gal). A fuel economy of 45 UK mpg therefore equals about 37.5 US mpg, which is 6.28 L/100 km either way. The US pint (473 mL) is also smaller than the imperial pint (568 mL).
How to use this tool
Enter a volume
Use the Liters or the UK gallons field; decimals are accepted, for example 12.5 gal.
Read the exact conversion
The other field updates as you type using the statutory factor; round to two decimals for a fill-up, to a whole number for a rough idea.
Use the table
The table under the converter lists common values (1, 2, 5, 10, 20, 50, 100 and 1,000) in both directions, handy for tanks of 8 to 15 gallons.
Liters ↔ UK gallons conversion formulas
The imperial gallon is defined directly in cubic decimetres by the 1985 UK law.
Liters to UK gallons
gal = L ÷ 4.54609 ≈ L × 0.219969
The 0.219969 factor is rounded to the millionth.
mpg (UK) to L/100 km
L/100 km = 282.481 ÷ mpg
Derived from 100 × 4.54609 ÷ 1.609344.
- L
- volume in liters (1 L = 1 dm³)
- UK gal
- volume in imperial gallons (1 UK gal = 4.54609 L)
- mpg
- miles per imperial gallon
Example: 12 UK gal = 12 × 4.54609 ≈ 54.55 L; and 40 L = 40 ÷ 4.54609 ≈ 8.80 UK gal.
Use cases
Cars and travel in the UK
Convert the imperial-mpg figures in British adverts and road tests into L/100 km.
Brewing and pubs
Convert pints (568 mL) and gallons used for beer and casks into liters.
Older documents and manuals
Read British data sheets, maps or books, and sources from Commonwealth countries, that quote imperial gallons.
Products and paint
Compare the size of paint cans, fuel containers or farm products sold by the gallon.
Examples
One imperial gallon in liters
1 × 4.54609 = 4.54609 L, which is 20% more than a US gallon.
Input
1 UK galResult
4.546 LA 12-gallon tank
12 × 4.54609 = 54.553 L, a common size for a British car.
Input
12 UK galResult
54.55 LA 40-liter fill-up
40 ÷ 4.54609 ≈ 8.799 imperial gallons.
Input
40 LResult
8.80 UK galFuel economy of 45 UK mpg
100 × 4.54609 ÷ (45 × 1.609344) = 6.28 L per 100 km.
Input
45 mpg (UK)Result
6.28 L/100 kmPrice per gallon
1.45 × 4.54609 ≈ £6.59 for 4.546 L, useful to compare with a price quoted per gallon.
Input
£1.45 per literResult
£6.59 per UK gallonTips and best practices
- Quick reference: 1 UK gal ≈ 4.55 L, 5 gal ≈ 22.7 L and 10 gal ≈ 45.5 L; 1 L ≈ 0.22 UK gal.
- An imperial gallon holds 8 pints of 568 mL; a US gallon holds 8 pints of 473 mL.
- To turn UK mpg into US mpg, divide by 1.20095; for L/100 km, use 282.481 ÷ UK mpg.
- When a source just says "gallon", check its country: the United States (3.785 L) or the United Kingdom (4.546 L).
Sources and references
- Weights and Measures Act 1985, Schedule 1 (opens in a new tab), legislation.gov.ukPage in English
- NIST, Guide for the Use of the International System of Units (SP 811), Appendix B.8: Factors for Units Listed Alphabetically (opens in a new tab)Page in English
Frequently asked questions
How many liters are in a British gallon?
One imperial (UK) gallon is exactly 4.54609 L, about 4.55 L. The value is set by the UK Weights and Measures Act 1985 (4.54609 dm³).
How do I convert liters to UK gallons?
Divide the liters by 4.54609, or multiply by 0.219969. For example, 50 L is about 11.00 UK gallons and 100 L about 22.00 gallons.
How do I convert UK gallons to liters?
Multiply the gallons by 4.54609. For example, 10 gallons is about 45.46 L and 15 gallons about 68.19 L.
What is the difference between a UK gallon and a US gallon?
The imperial gallon is 4.546 L and the US gallon 3.785 L: the British gallon is about 20% larger (1 UK gal ≈ 1.2009 US gal), and its pint holds 568 mL against 473 mL.
How many liters are in an imperial pint?
An imperial pint is one eighth of a gallon: 4.54609 ÷ 8 = 0.56826125 L, about 568 mL.
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