Are L/100km and km/L the same unit?

No. L/100km measures the fuel needed to drive 100 km, so smaller is better (reciprocal). km/L measures the distance per liter, so larger is better. This tool converts via 100 / (km/L).

What's the difference between US and UK mpg?

The gallon size: 1 US gal = 3.785411784 L, 1 UK (Imperial) gal = 4.54609 L. The UK gallon is ~20% larger, so the same car shows a larger mpg figure in the UK (e.g. 30 mpg US ≈ 36 mpg UK).

Can I convert WLTC / EPA hybrid figures too?

Yes — this tool is a pure unit conversion and does not depend on the measurement protocol (WLTC / JC08 / EPA / NEDC / WLTP). When comparing cars, make sure both numbers come from the same protocol.

Which constants are used?

1 mile = 1.609344 km (NIST exact), 1 US gal = 3.785411784 L (exact), 1 UK gal = 4.54609 L (exact). Every conversion is normalised to km/L first, then converted to the target unit.

Is my input uploaded?

No. All computation runs in your browser and the value never leaves the page.

Back to Convert

Fuel Economy Converter (km/L ⇄ L/100km ⇄ mpg)

Convert vehicle fuel economy between km/L (Japan, Nordic), L/100km (Europe, China, Australia), mpg US, and mpg UK. Handy when comparing a Japanese spec sheet against an EU/US one, or translating a rental car's mpg dashboard into km/L. Uses exact NIST factors (1 mile = 1.609344 km, 1 US gal = 3.785411784 L, 1 UK gal = 4.54609 L). Runs entirely in your browser — no uploads.

conversioncalculator

How to use

1) Pick the input unit (km/L, L/100km, mpg US, or mpg UK). 2) Enter a value — the other three units are computed instantly in the table. 3) Use the Copy button on each row to grab a single value. There's no run button; calculation is live.

FAQ

Are L/100km and km/L the same unit?: No. L/100km measures the fuel needed to drive 100 km, so smaller is better (reciprocal). km/L measures the distance per liter, so larger is better. This tool converts via 100 / (km/L).
What's the difference between US and UK mpg?: The gallon size: 1 US gal = 3.785411784 L, 1 UK (Imperial) gal = 4.54609 L. The UK gallon is ~20% larger, so the same car shows a larger mpg figure in the UK (e.g. 30 mpg US ≈ 36 mpg UK).
Can I convert WLTC / EPA hybrid figures too?: Yes — this tool is a pure unit conversion and does not depend on the measurement protocol (WLTC / JC08 / EPA / NEDC / WLTP). When comparing cars, make sure both numbers come from the same protocol.
Which constants are used?: 1 mile = 1.609344 km (NIST exact), 1 US gal = 3.785411784 L (exact), 1 UK gal = 4.54609 L (exact). Every conversion is normalised to km/L first, then converted to the target unit.
Is my input uploaded?: No. All computation runs in your browser and the value never leaves the page.

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