The formula
How it works
Work out what a journey will cost in fuel from its distance, your vehicle’s economy and the pump price. Switch between miles-and-MPG or kilometres-and-litres to match where you drive.
FAQ
How do I find my fuel economy?
Fill the tank, drive, then refill and note the fuel added and distance covered. Miles ÷ gallons gives MPG; for the metric figure, litres used ÷ distance × 100 gives L/100km.
Does this include a return trip?
No — enter the full distance you will drive. For a round trip, double the one-way distance before entering it, or type the total for the whole journey.
How can I split fuel cost with passengers?
Work out the total trip cost here, then divide it by the number of people sharing the ride to get a fair amount per person.
Does traffic or terrain affect the estimate?
The calculator assumes your entered fuel economy holds for the whole trip, but stop-start traffic, hills and highway speeds all change real-world economy. Use a figure from similar driving conditions for the most accurate estimate.
Why does my actual cost differ from the estimate?
Fuel prices vary by station and change often, and your real fuel economy depends on load, driving style and conditions on the day. Treat the result as a close planning estimate rather than an exact receipt.
Should I use city or highway fuel economy?
Use whichever matches the trip — city economy for stop-start driving, highway economy for steady long-distance cruising — or a blended figure if the route is a mix of both.
How do I account for a fuel-efficient versus a thirsty car?
Enter each vehicle’s own fuel economy figure and compare the resulting costs side by side; a car that uses more fuel per mile will always show a higher trip cost at the same price and distance.
About the fuel cost calculator
This calculator estimates how much fuel a trip will use and what it will cost, from the distance, your vehicle’s fuel economy and the current price at the pump. Fuel is one of the biggest running costs of driving, and a quick estimate helps you budget a journey, split costs with passengers, or compare the cost of driving with other ways of getting there.
How to use it
First choose your units: miles with MPG, or kilometres with litres per 100 km. Then enter the distance, your fuel economy and the price of fuel. For a 300-mile trip in a car doing 30 MPG with fuel at $3.50 a gallon, the trip needs 10 gallons and costs $35. In metric, 300 km at 8 L/100km with fuel at $1.60 a litre uses 24 litres. Adjust any figure to see how a thirstier car or a pricier pump changes the total.
The formula
In imperial units the cost is , where is the distance in miles, is the economy in miles per gallon and is the price per gallon; the first part, , is the gallons used. In metric the fuel used is with in litres per 100 km, then multiplied by the price per litre. Either way you find the fuel quantity first, then multiply by its price.
Where it is used
Drivers use it to budget commutes, holidays and long road trips, and to work out a fair share when carpooling. Delivery drivers and small businesses use it to price jobs that involve travel and to claim mileage. It is also handy when choosing between two cars, since the running cost of a fuel-hungry model over a year of driving can dwarf the difference in sticker price.