EV charging cost calculator
What a charge costs at home or on the public network, the cost per mile and per year, and how that compares with petrol.
Cost of 100 miles: home, public and petrol
With our example assumptions (3.3 miles per kWh, 10% charging losses, a 45 mpg petrol or diesel car):
| Fuel | Price | 100 miles |
|---|---|---|
| Home charging, price cap rate | 26.32p/kWh | £8.86 |
| Public standard/fast charger (pay as you go) | 54p/kWh | £18.18 |
| Public rapid/ultra-rapid charger (pay as you go) | 79p/kWh | £26.60 |
| Petrol car, 45 mpg | 174.88p/litre | £17.67 |
| Diesel car, 45 mpg | 199.52p/litre | £20.16 |
Home charging at the default price-capped rate already costs about half as much per mile as petrol in this example. Off-peak EV tariffs widen the gap; pay-as-you-go rapid charging can cost more than petrol.
How the calculation works
Energy added = battery size × (charge to − charge from). Energy paid for = energy added ÷ (1 − losses). Cost = energy paid for × price per kWh. Cost per mile = price ÷ (miles per kWh × (1 − losses)). Petrol: miles ÷ mpg × 4.546 litres per gallon × price per litre.
Prices: home default is the Ofgem price cap unit rate for 1 October to 31 December 2026 (26.32p per kWh, no VAT on domestic electricity until 31 March 2027). Public prices are Zapmap's weighted average pay-as-you-go rates for September 2026. Fuel is the UK average pump price from the government's weekly road fuel prices for 5 October 2026.
Charging overnight on a time-of-use tariff is usually the cheapest option; to charge when the grid is cleanest, check the best time to use electricity. Read more about electric vehicles and clean transport.
Frequently asked questions
How much does it cost to charge an electric car at home?
It depends on battery size and your tariff. Adding 36 kWh (60% of a 60 kWh battery) takes about 40 kWh from the wall once charging losses are included; at the price cap rate of 26.32p per kWh that is about £10.53. On an off-peak EV tariff the same charge can cost a fraction of that: type your rate into the calculator.
How much does public charging cost?
Zapmap's weighted average pay-as-you-go price for September 2026 was 54p per kWh on standard and fast chargers (up to 49 kW) and 79p per kWh on rapid and ultra-rapid chargers (50 kW and above). Memberships and offers can be cheaper.
Is an electric car cheaper to run than petrol?
Charged at home, usually yes. With our example assumptions (3.3 miles per kWh, 45 mpg), 100 miles costs about £8.86 on home electricity at the price cap rate against about £17.67 of petrol. Relying on rapid chargers can make it dearer than petrol.
What are charging losses?
Some energy is lost as heat in the charger, cable and battery, so you pay for more kWh than end up in the battery. We assume 10% by default; real losses vary with the charger, the car and the weather.
How many miles per kWh does an electric car do?
Commonly around 3 to 4 miles per kWh, less for large SUVs, in cold weather and at motorway speeds. We use 3.3 as a default; your car's trip computer shows your real figure.
General information, not financial advice. Sources: Ofgem, Zapmap, DESNZ weekly road fuel prices.