Fuel Economy Converter

1. Select your input unit. Choose the unit your car uses: MPG (US) for American vehicles, MPG (Imperial) for UK vehicles, L/100km for most of Europe and Canada, or km/L for some Asian markets.
2. Type your value. Enter the fuel economy figure and all four conversions appear instantly. The active input unit is highlighted.
3. Compare across markets. Shopping for a car listed with European specs? Convert L/100km to mpg (US) to compare it with American vehicles. A car rated at 6 L/100km equals about 39.2 mpg US.
4. Fuel cost estimate. The panel at the bottom estimates annual US fuel cost at $3.50/gallon and 15,000 miles per year, giving you a rough cost-of-ownership comparison between vehicles with different efficiency ratings.

Example: a Honda Civic rated at 36 mpg (US highway). Type 36 with MPG (US) selected to see: 43.2 mpg UK, 6.53 L/100km, 15.3 km/L.

All conversions route through L/100km as the intermediate unit:

MPG (US) to L/100km:  L/100km = 235.214 / MPG (US)
L/100km to MPG (US):  MPG (US) = 235.214 / L/100km

MPG (UK) to L/100km: L/100km = 282.481 / MPG (UK)
L/100km to MPG (UK): MPG (UK) = 282.481 / L/100km

km/L to L/100km:     L/100km = 100 / km/L
L/100km to km/L:     km/L = 100 / L/100km

The conversion constants come from gallon and distance definitions:

Note: MPG and km/L are "higher is better" (more distance per unit of fuel), while L/100km is "lower is better" (less fuel per unit of distance). A car with better fuel economy has a higher MPG and lower L/100km.