Electric vs petrol/diesel running cost calculator
Compare a year of electric charging against a year of petrol or diesel, for your real mileage and rates - plus an optional break-even if you know the purchase-price difference between the two cars.
How this is calculated
Straightforward arithmetic, not a simulation: your annual mileage divided by the EV's efficiency gives the kWh used per year, priced at a blend of your home rate and (if given) your public/rapid rate weighted by how much of your charging happens each way. The same mileage divided by the petrol/diesel car's mpg, converted from UK gallons to litres, gives the fuel used per year, priced at your fuel cost per litre. The break-even, if you give a purchase-price difference, is simply that figure divided by the annual saving.
Not sure what home charging rate to enter? Our EV tariff comparison shows which plans give the whole house a cheaper window and which discount only eligible car charging.
Common questions
Where do I find my car's efficiency or fuel economy?
Your car's own trip computer/app over a few weeks of normal driving is more realistic than the official WLTP figure, which tends to be optimistic. If you don't have a real figure yet, the default here is a reasonable average to start from.
Why does this ask about public/rapid charging separately?
Public and rapid charging is usually priced far higher than charging at home, so an EV driver who relies on it more often has a meaningfully higher real running cost than a pure home-charging estimate would suggest.
What does the break-even figure include?
Only the purchase-price difference you enter against the annual running-cost saving - it doesn't include grants, servicing/insurance differences, or either vehicle's resale value.
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