Fuel Cost per Mile (and per km) Calculator
Find out what each mile or kilometre costs you in fuel and what you spend over a week, a month or a year. Works with MPG or L/100 km and prices per gallon or per litre.
Your car
How much you drive
Your fuel bill
How to calculate fuel cost per mile
Divide the price of a gallon by how many miles the car goes on it. With litres and kilometres, multiply the litres per 100 km by the price per litre and divide by 100:
cost per km = L/100 km ÷ 100 × price per litre
At the US average of $4.23/gal, a car that gets 30 MPG costs $0.141 a mile in gas. Over 12,000 miles a year that is about $1,690.
In the UK, with petrol at 174.1p/L, a car doing 45 MPG costs 17.6p a mile, or about £1,407 for 8,000 miles a year.
Fuel cost isn't the full cost of driving
The number above is fuel only. The full cost per mile of owning a car also includes depreciation, insurance, servicing, tyres, tax and parking, which together usually add up to more than the fuel. Mileage allowances paid by employers, such as the IRS standard mileage rate in the US or HMRC's approved mileage rates in the UK, are meant to cover all of these, which is why they are much higher than the fuel cost alone.
Ways to lower your cost per mile
- Combine short trips. A cold engine uses much more fuel for the first few miles.
- Keep tyres at the right pressure and remove roof racks when you don't need them.
- Drive smoothly. Gentle acceleration and keeping to the speed limit save more fuel than most gadgets.
- Compare an electric car. The EV charging cost calculator shows the cost per mile on home electricity.