How charging cost is worked out
Energy needed = battery kWh × (charge to % − charge from %) ÷ 0.9
Cost = energy needed × price per kWh
The ÷ 0.9 allows for about 10% of energy lost as heat while charging, which you pay for but which never reaches the battery. Adding 20% to 80% on a 60kWh battery takes 36kWh into the battery and about 40kWh from the meter. At the 26.32p price cap that is £10.53, giving roughly 126 miles.
Cost per mile by where you charge
| Where | Typical price per kWh | Cost per mile at 3.5 miles/kWh | Cost of 1,000 miles |
|---|---|---|---|
| Home, EV off-peak tariff | 7p | 2.2p | £22 |
| Home, standard price cap | 26.32p | 8.4p | £84 |
| Public slow or fast charger | 54p | 17.1p | £171 |
| Public rapid charger | 77p | 24.4p | £244 |
| For comparison: petrol car at 45mpg | 174.5p a litre | 17.6p | £176 |
Price cap: Ofgem, 1 October to 31 December 2026, average direct debit unit rate. Public charging: Zapmap average prices, August 2026. Off-peak: typical overnight EV tariff rate.
Home charging is where the savings are
On an overnight EV tariff, an electric car can cost around 2p a mile to run, about a tenth of the cost of petrol. On the standard price cap it is still roughly half. Relying on public rapid chargers can cost about the same as, or more than, a petrol car, so drivers without a driveway should look at slower public chargers, workplace charging or charger subscriptions.
Why charge to 80%?
Rapid chargers slow down a lot above about 80% to protect the battery, and many manufacturers recommend keeping daily charging between 20% and 80%. Charging to 100% is fine before a long trip.
Electric car tax and the coming pay-per-mile charge
Electric cars now pay vehicle tax: £10 in the first year and £200 a year after that. The government has also announced an electric vehicle excise duty (eVED) of 3p a mile from April 2028, and 1.5p a mile for plug-in hybrids. Use the car tax calculator for VED.
Sources
- Ofgem: Energy price cap
- Zapmap: EV charging price index
- GOV.UK: Vehicle tax for electric vehicles
- GOV.UK: Electric Vehicle Excise Duty (eVED)
Rates and rules last checked 15 October 2026. These figures are a guide. For a decision that matters, confirm with the official source.