Fuel Economy Converter
Convert MPG, L/100km and km/L. US and imperial gallons differ, so US MPG and UK MPG are listed separately.
Note. L/100km is an inverse measure — a lower number means better economy — so converting to or from it uses a reciprocal, not a multiplication.
Popular fuel economy conversions
Fuel Economy unit reference chart
What one of each unit is worth in kilometers per liter, the base unit used for every conversion in this category.
| Unit | Symbol | 1 unit in km/L |
|---|---|---|
| miles per US gallon | MPG (US) | 0.4251437074 km/L |
| miles per imperial gallon | MPG (UK) | 0.3540061899 km/L |
| liters per 100 kilometers | L/100km | — |
| kilometers per liter | km/L | 1 km/L |
| miles per liter | mi/L | 1.609344 km/L |
Fuel Economy units explained
Miles per US gallon (MPG (US))
Miles per US gallon is the fuel economy figure used on American window stickers. A US gallon is smaller than an imperial gallon, so US MPG figures are about 17% lower than UK MPG for the same car.
Miles per imperial gallon (MPG (UK))
Miles per imperial gallon is the figure quoted in the UK. The imperial gallon is 4.54609 litres, about 20% larger than the US gallon.
Liters per 100 kilometers (L/100km)
Liters per 100 kilometers is the standard fuel consumption figure in Europe and Canada. Unlike MPG, lower is better.
Kilometers per liter (km/L)
Kilometers per liter is the fuel economy unit used in much of Asia, Africa and South America. Higher is better.
Frequently asked questions
What is the base unit of fuel economy?
This converter routes every fuel economy conversion through the kilometer per liter. Converting from one unit to another means converting to kilometer per liters first and then out again, which keeps every pair consistent with every other pair.
How accurate are these fuel economy conversions?
Results are shown to 10 significant digits using exact defined factors wherever a unit has one. L/100km is an inverse measure — a lower number means better economy — so converting to or from it uses a reciprocal, not a multiplication.
All fuel economy conversions
Every fuel economy conversion page on this site, 18 in total.