How to use the fuel cost calculator
- Choose US units (miles, mpg) or metric (km, L/100 km).
- Enter the trip distance and your vehicle’s fuel economy.
- Enter the price per gallon or litre.
- Tick Round trip to double the distance.
MPG vs. L/100 km
Miles per gallon measures how far you go on a fixed amount of fuel, so higher is better. Litres per 100 km measures how much fuel you use over a fixed distance, so lower is better. To convert, divide 235.21 by one to get the other: 30 mpg (US) is about 7.8 L/100 km.
Getting a realistic number
- Use your car’s real-world economy rather than the official figure; most trip computers show it.
- Motorway driving at high speed, heavy loads, roof boxes and cold weather all increase consumption.
- Split the result by the number of passengers to share costs fairly.
Examples
10 gallons · $35.00
65 litres · €117.00