Gas Mileage Calculator

Enter the distance driven and fuel used to get your fuel economy in MPG, km/L and L/100km.

How this calculator arrives at its answer

This calculator works out your real-world fuel economy from a full tank. Enter how far you drove and how much fuel you used, in your choice of units.

Track it over time to spot changes in your car’s efficiency.

A worked example

As an example, with a distance driven of 300, fuel used of 10, the calculator returns a fuel economy of 30. Underneath, L / 100 km comes out at 7.84 and km / L at 12.75. Change any field and every figure updates as you type.

Getting your answer

  1. Enter the distance driven and its unit.
  2. Enter the fuel used and its unit.
  3. Read MPG, km/L and L/100km.

How the number is calculated

MPG = miles ÷ gallons L/100km = litres ÷ km × 100

Common questions

How do I calculate MPG?
Divide the miles driven by the gallons of fuel used to refill. Fill up, reset the trip meter, and refill to measure a tank.
What’s a good fuel economy?
It varies widely by vehicle. Higher MPG (or km/L) and lower L/100km mean better efficiency.
How is L/100km different?
It measures fuel per fixed distance, so lower is better — the opposite direction to MPG.