To convert mpg (UK) to L/100 km, use L/100 km = 282.481 ÷ (mpg (UK)) — you divide, not multiply. For example, 40 mpg (UK) equals 7.06202 L/100 km. Enter any value above and the result appears instantly — free and entirely in your browser, with nothing uploaded.
How do you convert mpg (UK) to L/100 km?
The conversion formula is L/100 km = 282.481 ÷ (mpg (UK)). mpg (UK) and L/100 km measure the same thing from opposite ends — one states fuel per distance, the other distance per fuel. That is why you divide by your own value instead of multiplying: a small mpg (UK) figure means a large L/100 km figure, and vice versa.
mpg (UK) to L/100 km conversion table
| mpg (UK) | L/100 km |
|---|---|
| 25 mpg (UK) | 11.2992 L/100 km |
| 30 mpg (UK) | 9.41603 L/100 km |
| 35 mpg (UK) | 8.07088 L/100 km |
| 40 mpg (UK) | 7.06202 L/100 km |
| 50 mpg (UK) | 5.64962 L/100 km |
| 60 mpg (UK) | 4.70802 L/100 km |
What is mpg (UK) (mpg (UK))?
Miles per gallon (UK) uses the imperial gallon of 4.54609 litres, about 20% larger than the US gallon. The same car therefore scores roughly 20% more mpg in British figures than in American ones.
What is L/100 km (L/100 km)?
Litres per 100 kilometres (L/100 km) is the European way to state fuel use: how much fuel a car burns over a fixed distance. Lower is better. It is a consumption figure and therefore the inverse of mpg.
Why convert mpg (UK) to L/100 km?
Europe states fuel use as consumption (litres per 100 km, lower is better), the US and UK as economy (miles per gallon, higher is better), and much of Asia as kilometres per litre. The two families are inverses of each other, which is why a car advert from abroad is so hard to read at a glance.
The US gallon is defined as exactly 231 cubic inches, or 3.785411784 litres; the imperial gallon is exactly 4.54609 litres (UK Weights and Measures Act 1985). That gives two different constants: mpg (US) = 235.2146 ÷ (L/100 km) and mpg (UK) = 282.4809 ÷ (L/100 km).
What can the converter not tell you?
The converter turns one figure into another; it does not measure anything. Factory values follow the WLTP test cycle and regularly sit below what a car uses on the road, and driving style, load, tyres and temperature shift the result far more than any conversion does. A value of 0 has no counterpart either: a car that burns nothing would travel infinitely far, so the field stays blank instead of showing a number.
How to convert mpg (UK) to L/100 km
- Enter the value in mpg (UK) into the left field of the converter.
- Read the result in L/100 km instantly in the right field — it updates automatically.
- Use the swap button to reverse the direction (L/100 km to mpg (UK)).
The converter runs entirely in your browser: no uploads, no queue, no limits. You can even use it offline.