Fuel cost calculator
What a car costs to fuel each year and each month. Petrol and diesel from mpg and the pump price; electric from kWh per mile and your tariff.
How we work it out
Petrol and diesel: miles a year divided by mpg gives gallons, times 4.54609 litres per UK gallon, times the price per litre.
Electric: miles a year times kWh per mile, times the price per kWh. Home charging on an off-peak tariff usually costs far less per kWh than rapid public chargers, so use the mix you expect.
Real-world economy is usually below the official figure, especially on short trips and in cold weather. Your own figure is the best one to use.
Questions people ask
Why 4.54609 litres per gallon?
UK mpg figures use the imperial gallon, which is exactly 4.54609 litres. A US gallon is smaller (about 3.785 litres), so US mpg figures are not comparable with UK ones.
How do I work out my car's real mpg?
Fill the tank, reset the trip, drive as normal, then fill it again. Divide the miles by the litres you put in, then multiply by 4.54609.
How do I turn miles per kWh into kWh per mile?
Divide 1 by it. For example, 4 miles per kWh is 0.25 kWh per mile. The calculator does this for you if you pick miles per kWh.
What price should I use?
The price on your local forecourt, or the rate on your electricity tariff. The calculator starts with example figures, so put in your own.