Plan a road trip budget or split the cost of a drive fairly. Enter the distance, your car’s fuel efficiency and the fuel price, in metric or US units.
Formula
Cost = Distance ÷ Fuel economy × Price per gallon
In metric units, where consumption is given in litres per 100 km: Cost = Distance × (L/100 km) ÷ 100 × Price per litre.
Worked example
A 250-mile trip in a car that does 30 mpg uses 250 ÷ 30 ≈ 8.33 gallons. At $3.50 a gallon that costs about $29.17.
Converting fuel economy
To convert mpg (US) to L/100 km, divide 235.21 by the mpg: 30 mpg ≈ 7.84 L/100 km.
Frequently asked questions
How do I calculate fuel cost for a trip?
Divide the distance by your fuel economy to get the fuel needed, then multiply by the price per unit of fuel.
How can I find my car’s real fuel economy?
Fill the tank, reset the trip meter, drive normally, then refill. Divide the distance driven by the fuel added.
Last updated · Calculations checked by automated tests· Editorial policy