MPG Calculator: Gas Mileage and Fuel Economy
Work out your car's real fuel economy from the distance driven and the fuel used, in MPG (US and UK), L/100 km and km/L, plus the cost per mile or km.
What it does
Fuel economy is the distance a car travels on a given amount of fuel. In the US it is measured in miles per US gallon (mpg), in the UK in miles per imperial gallon, which is about 20% larger, and in most other countries in litres per 100 km or kilometres per litre. The calculator converts between all of them and, with the fuel price, shows how much each mile or kilometre costs.
How to use it
- Fill the tank and reset the trip metre (or write down the odometer).
- At the next fill-up, type the distance driven and how much fuel it took to fill the tank again.
- See your MPG, L/100 km and km/L, and type the price to get the cost per mile or km.
The arithmetic runs in your browser. Nothing you type is sent anywhere and nothing is stored, so you can use these with real numbers.
Frequently asked questions
How do I calculate MPG?
Divide the miles driven by the gallons used. 300 miles on 10 US gallons is 30 mpg, which equals 7.84 L/100 km or 12.75 km/L.
Why are UK mpg figures higher than US ones?
The imperial gallon used in the UK is 4.546 litres and the US gallon 3.785 litres. A car that does 30 mpg in the US does 36 mpg in the UK.
How do I convert L/100 km to km/L?
Divide 100 by the L/100 km figure: 8 L/100 km is 12.5 km/L. A car that uses 40 litres for 500 km does exactly that.
β½ Fuel Cost Calculator
β½ Fuel Consumption Converter
π·οΈ Unit Price Calculator: Compare Prices per Unit
Wikipedia — Fuel economy in automobiles
FuelEconomy.gov (U.S. DOE / EPA)