Fuel consumption converter
Convert L/100 km, MPG (US/UK) and km/L, and estimate a trip’s cost.
- Instant
- Free
- Private (processed locally)
- No sign-up
Compare consumption, however it is shown
A US spec sheet quotes MPG, a European one L/100 km. This tool puts everything on the same basis and even prices your next trip.
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Enter the consumption
In the displayed unit (L/100 km, US/UK MPG, km/L).
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Read the equivalents
The other three units compute live.
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Estimate a trip
Distance and price per litre give litres and cost.
A few equivalents
| L/100 km | US MPG | UK MPG | km/L |
|---|---|---|---|
| 5 | 47.0 | 56.5 | 20.0 |
| 6 | 39.2 | 47.1 | 16.7 |
| 8 | 29.4 | 35.3 | 12.5 |
| 10 | 23.5 | 28.2 | 10.0 |
Bases: 1 US gallon = 3.785 L, 1 UK gallon = 4.546 L. Everything is computed in your browser.
Frequently asked questions
How do I go from L/100 km to MPG?
MPG (miles per gallon) is inversely proportional to L/100 km. For the US gallon: MPG = 235.21 ÷ (L/100 km). So 8 L/100 km is about 29.4 US MPG. The larger UK gallon gives 282.48 ÷ (L/100 km), i.e. 35.3 UK MPG.
Why do US and UK MPG differ?
The US gallon (3.785 L) is smaller than the UK gallon (4.546 L). For the same real consumption, UK MPG is therefore always higher than US — by about 20%.
Which unit is most intuitive?
In Europe people think in L/100 km: the lower the number, the less fuel used. In the US and UK people use MPG: the higher, the better. The two logics are opposite, which is why converting helps.
How is a trip’s cost computed?
Multiply consumption (L/100 km) by distance, divided by 100, to get litres used, then by the price per litre. For example, 8 L/100 km over 100 km at €1.80 per litre costs 8 L × 1.80 = €14.40.