Fuel Converter
Convert L/100 km, km/L, and US or UK mpg.
Enter a value, choose the units, and see the result plus every other fuel economy unit.
Liters per 100 km → Miles per US gallon
Fuel Economy Converter
Convert fuel consumption between liters per 100 km, kilometers per liter, US miles per gallon, UK miles per gallon, miles per liter, and US gallons per 100 miles. Comparing a European car review with an American one, or planning a road trip abroad, becomes a single step.
Two kinds of fuel economy scales
Fuel figures come in two opposite styles:
- Consumption – fuel used per distance: L/100 km (Europe, Turkey, Australia, Canada) and gal/100 mi (on newer US window stickers). Lower is better.
- Economy – distance per fuel: km/L (Japan, India, Latin America), mpg (US and UK). Higher is better.
Because one is the reciprocal of the other, conversion is not a simple multiplication – doubling the mpg does not halve the L/100 km in a linear way on the gauge you are used to. The converter handles the inverse math for you.
Reference values
| L/100 km | km/L | mpg (US) | mpg (UK) |
|---|---|---|---|
| 4 | 25 | 58.8 | 70.6 |
| 6 | 16.7 | 39.2 | 47.1 |
| 8 | 12.5 | 29.4 | 35.3 |
| 10 | 10 | 23.5 | 28.2 |
| 15 | 6.7 | 15.7 | 18.8 |
Worked example
A US review lists 40 mpg. Select Miles per US gallon, enter 40, and the table shows about 5.88 L/100 km and 17.0 km/L. If the review was British, choose Miles per imperial gallon instead – 40 UK mpg is about 7.06 L/100 km.
Tips for accurate comparisons
Official figures come from different test cycles (WLTP, EPA, NEDC), so identical numbers after conversion still may not mean identical real-world economy. For trip planning, convert your distance with the Length Converter and fuel quantities with the Volume Converter.
Frequently Asked Questions
How do I convert L/100 km to mpg?
Divide 235.215 by the L/100 km value to get US mpg, or 282.481 by it to get UK (imperial) mpg. 6 L/100 km is about 39.2 mpg (US) or 47.1 mpg (UK).
Why are US and UK mpg different?
An imperial gallon is 4.546 liters while a US gallon is 3.785 liters. The same car therefore travels more miles per imperial gallon, so UK mpg figures are about 20% higher.
Why does a lower L/100 km mean better economy?
L/100 km measures fuel consumed per distance, so less is better. km/L and mpg measure distance per fuel, so more is better. The two scales are reciprocals of each other.