UK Electric Car Running Cost Calculator

Working out whether an electric car actually saves you money depends on more than just the price at the pump versus the price per kWh. Your mileage, how much you charge at home versus in public, your insurance and servicing costs, and the newly introduced road tax on electric vehicles all play a part. This calculator brings all of that together into a single annual running cost, with a direct comparison against an equivalent petrol car.

How to use the EV running cost calculator

Enter your annual mileage and your car's efficiency in miles per kWh, which typically falls between 3 and 4 for most electric cars. Add your home electricity rate, the share of your charging you expect to do at home versus in public, and a public charging rate. Then add your estimated annual insurance, servicing and road tax (VED), which now applies to electric cars following the April 2025 rule change. Finally, enter a petrol comparison MPG and price per litre, and optionally the price difference between the electric car and an equivalent petrol model, to see an estimated payback period.

How the calculation works

Total electricity used is your annual mileage divided by your car's miles per kWh figure. That usage is then split between home and public charging based on the percentage you enter, each costed at its own rate, since public charging is usually considerably more expensive per kWh than a typical home tariff. Your annual running cost adds this electricity cost to your insurance, servicing and VED. For the petrol comparison, the calculator works out how many litres an equivalent car would use at your chosen MPG, using the standard conversion of 4.54609 litres per gallon, then multiplies that by your petrol price per litre.

If you enter a price difference between the electric car and a comparable petrol model, the calculator divides that figure by your annual fuel savings to estimate a simple payback period in years. For the full band-by-band detail on what your specific car will actually pay in VED, our road tax calculator covers first-year and standard rates for every fuel type.

Worked example

Take a driver covering 8,000 miles a year in an electric car doing 3.5 miles per kWh, charging 80% at home at 25.7p per kWh and the rest on public chargers at 60p per kWh, with £650 insurance, £150 servicing and £195 VED a year.

Total electricity used comes to 8,000 ÷ 3.5 = 2,286 kWh a year, split into 1,829 kWh at home and 457 kWh in public. Electricity cost comes to around £744 a year. Adding insurance, servicing and VED brings the total annual running cost to around £1,739, or about 21.7p a mile.

An equivalent 40mpg petrol car covering the same 8,000 miles a year at £1.50 a litre would use around 909 litres of fuel, costing around £1,364 a year on fuel alone, roughly £620 a year more than the electric car's electricity cost. If the electric car cost £3,000 more to buy, that difference would take a little under 5 years to pay back purely through fuel savings, before accounting for any difference in insurance, servicing or resale value.

Why your charging mix matters so much

The single biggest factor in whether an EV genuinely saves you money is how much of your charging happens at home on a cheap tariff versus how much relies on public rapid chargers. Drivers with a driveway or garage who charge overnight, sometimes on a specific EV tariff with cheaper off-peak rates, tend to see the biggest savings versus petrol. Drivers without home charging access who rely mostly on public chargepoints see a much smaller gap, and in some cases little to no saving at all, since rapid charging prices can approach petrol-equivalent costs per mile.

Common mistakes when comparing EV and petrol running costs

A common mistake is comparing only fuel or electricity cost and ignoring that electric cars now pay VED too, following the rule change from April 2025, so the total cost gap with petrol is smaller than it used to be. Our UK car tax 2026 VED guide covers exactly how the rates compare across fuel types. It is also easy to overlook that electric cars are exempt from the London Ultra Low Emission Zone charge, which can be a meaningful saving for regular London drivers on top of any fuel saving. Our London driving charges guide explains ULEZ and the Congestion Charge in full.

Related calculators

To work out the exact fuel cost of a specific journey or trip, use our fuel cost calculator. If you want to compare two specific petrol or diesel cars by fuel economy, our MPG calculator can help. For the full VED breakdown on any vehicle, see our road tax calculator, and if you regularly drive into central London, our Congestion Charge and ULEZ calculator shows what you could save by switching to an electric car.