Fuel Economy Calculator
Calculate your vehicle's fuel economy in km/L, L/100km, and MPG from a trip's distance and fuel used, instantly in your browser.
How to use the Fuel Economy Calculator
- Fill your tank and reset the trip meter.
- Drive normally, then refill the tank and note how many liters it took.
- Enter the distance traveled in kilometers and the fuel used in liters.
- Click Run to see your fuel economy in km/L, L/100km and US MPG.
How the Fuel Economy Calculator works
Using the distance and fuel from a real trip gives a more honest figure than the manufacturer's rating:
km/L = Distance ÷ Fuel usedL/100km = Fuel used ÷ Distance × 100
US miles per gallon is derived from km/L using the conversion factor 1 km/L ≈ 2.352 MPG. Note that L/100km is a consumption figure, so lower is better, while km/L and MPG are economy figures where higher is better. Averaging over several fill-ups smooths out differences in driving conditions.
Frequently asked questions
- Is this fuel economy calculator free?
- Yes. Calculate your fuel economy at no cost, with no account required.
- How is fuel economy calculated?
- km/L = distance / fuel used. L/100km = (fuel used / distance) x 100. MPG (US) is derived from km/L using the standard conversion factor.
- What's the difference between this and the Fuel Economy Converter?
- This tool calculates your fuel economy from real trip data (distance and fuel used); the Fuel Economy Converter converts an already-known fuel economy value between units.