Convert UK Gallon to Liter (gal (UK) → L)

Converting UK gallons to liters is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in UK gallons

   Start with the number of UK gallons (gal (UK)) you want to convert.
2. 2
   Multiply by 4.54609

   The conversion factor from gal (UK) to L is 4.54609. Multiply your value by this number.
3. 3
   Read the result in liters

   The result is your value in liters (L).

Multiply the value in UK gallons by 4.54609. For the reverse direction, multiply by 0.219969.

• ✓1 UK gallon = 4.54609 L exactly = 160 UK fluid ounces.
• ✓1 UK gallon ≈ 1.201 US gallons.
• ✓UK mpg × 0.832 = US mpg (same car, different unit).

• ✗Comparing UK mpg with US mpg directly — UK figures are about 20% higher for the same car.
• ✗Using 4.5 L instead of 4.546 L for precise conversion.
• ✗Assuming modern UK car ads quote US gallons — they always use UK gallons.

What is the UK Gallon?

The UK imperial gallon equals exactly 4.54609 liters and is approximately 20% larger than the US gallon. Established by the British Weights and Measures Act of 1824 to standardize earlier ale and corn gallons, the imperial gallon was designed so that 10 pounds of pure water at 62°F occupied exactly 1 gallon. Although the United Kingdom has officially adopted the liter for fuel sales since 1995, the imperial gallon persists in everyday speech ('miles per gallon' for car fuel economy) and remains the standard unit in some Caribbean and Pacific Commonwealth countries. The imperial gallon relates to the US gallon (1 imp gal ≈ 1.201 US gal), the imperial quart (4 imp qt = 1 imp gal), the imperial pint (8 imp pt = 1 imp gal — the famous British pint of beer), and the liter (1 imp gal ≈ 4.546 L).

• UK fuel economy in miles per gallon (UK mpg)
• Older British industrial and brewing contexts
• Commonwealth countries that retain imperial measures

What is the Liter?

The liter equals exactly 1 cubic decimeter (1 dm³ = 0.001 m³) and is the everyday metric unit for liquids worldwide. Adopted as part of the metric system in the 1790s, the liter is used universally for beverages, fuel, household chemicals, and cooking liquids — except in the United States where gallons and fluid ounces dominate. The liter has special connection to mass: pure water at 4°C has almost exactly 1 kg per liter, a relationship designed into the metric system. Soda, milk, and water bottles in metric countries come in 0.5 L, 1 L, 1.5 L, and 2 L sizes. The liter relates to the milliliter (1,000 mL = 1 L), the cubic meter (1,000 L = 1 m³), the US gallon (1 L ≈ 0.264 gal), and the UK gallon (1 L ≈ 0.220 imp gal). Although not strictly an SI base unit, the liter is one of the most-used metric units globally.

• Bottled beverages and milk in Europe
• Petrol and diesel pricing in metric countries
• Engine displacement (car engines rated in litres)