Convert Liters per 100 km to MPG (UK)
Liters per 100 km to miles per gallon (UK) is the conversion you need when a car's fuel economy is quoted the metric way but you think in imperial miles per gallon. The catch that surprises people: liters per 100 km measures fuel used per distance, so it's the reverse of mpg. A lower L/100km is better economy, and a lower number becomes a bigger mpg. You divide instead of multiply: mpg (UK) = 282.480936 ÷ (L/100km).
Liters per 100 km to Miles per gallon (UK) conversion table
| Liters per 100 km (L/100km) | Miles per gallon (UK) (mpg (UK)) |
|---|---|
| 1 | 282.480936 |
| 2 | 141.240468 |
| 3 | 94.160312 |
| 5 | 56.496187 |
| 10 | 28.248094 |
| 20 | 14.124047 |
| 50 | 5.649619 |
| 100 | 2.824809 |
| 500 | 0.564962 |
| 1,000 | 0.282481 |
The formula
Liters per 100 km and miles per gallon run in opposite directions — one counts fuel per distance, the other counts distance per fuel — so you divide rather than multiply. To convert liters per 100 km to UK mpg, divide 282.480936 by the L/100km figure:
mpg (UK) = 282.480936 ÷ (L/100km)
Because it's a division, a smaller L/100km gives a larger mpg. That's the heart of it: less fuel used per 100 km means more miles from every gallon.
A worked example
Say a car is rated at 8 L/100km and you want it in UK mpg:
282.480936 ÷ 8 = 35.31 mpg (UK)
So 8 L/100km is about 35.31 miles per gallon. See how a modest 8 on the metric side turns into 35.31 on the mpg side — the two scales run opposite each other, so a small number flips into a big one.
Why it's an approximation
The 282.480936 constant folds together the miles-to-kilometers and gallons-to-liters conversions, and those underlying numbers don't divide evenly. So the result comes out rounded for everyday use — fine for comparing cars, just not exact to the last decimal.
The gallon matters here too. This page uses the UK (imperial) gallon, which is about 20% bigger than the US gallon. That's why the same car reads higher in UK mpg than in US mpg, and why this constant is larger than the US one. Always check which gallon a figure uses before comparing cars.
When you'll use it
Reading a car's fuel economy from a metric spec sheet and wanting it in imperial miles per gallon, comparing figures against UK road-test numbers, or making sense of a listing that only quotes L/100km.
Frequently asked questions
Why do I divide instead of multiply to get mpg?
Because the two measures run in opposite directions. Liters per 100 km counts fuel used per fixed distance, while miles per gallon counts distance covered per fixed fuel. One is the flip of the other, so you divide 282.480936 by the L/100km figure rather than multiplying. A small L/100km gives a big mpg.
Why is the UK mpg number higher than the US one for the same car?
Because the UK (imperial) gallon is about 20% bigger than the US gallon. A bigger gallon covers more miles, so the same car scores a higher mpg on the UK scale. That's why the UK constant, 282.480936, is larger than the US one.
Does a lower liters-per-100km number mean better or worse economy?
Lower is better. Fewer liters to cover 100 km means the car uses less fuel, so 6 L/100km beats 9 L/100km. It's the opposite of mpg, where higher is better — which is exactly why the two scales feel backwards to each other.