Fuel economy units

Enter either MPG or L/100 km; the other field updates on Calculate. The relationship is standard algebra from distance and volume definitions. Driving style, temperature, and test cycles mean real-world consumption will differ from any single number.

Uses 235.214583 ÷ MPG = L/100km (US gallon definition).

FAQ

What constant links US MPG and L/100 km?

The script uses 235.214583 ÷ MPG ≈ L/100 km and 235.214583 ÷ (L/100 km) ≈ MPG (US liquid gallon, statute mile). You can fill either field; both update when valid. Not UK imperial MPG.

Does the decimal separator matter?

This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.