How much does it cost to charge an electric car at home?
Work out what charging your electric car at home costs per year, per month and per 100 miles, including charging losses. About £8 per 100 miles at the UK price cap for a 3.5 mi/kWh car.
- Per month
- —
- Per 100 km
- —
- Charge from 10% to 80%
- —
- Electricity drawn from the grid per year
- —
Method: energy into the battery = distance × efficiency; energy you pay for = battery energy × (1 + losses). Default losses from ADAC measurements (2026): 5–7% on a wallbox, 13–24% on a domestic socket. Results are indicative estimates based on the values you enter. Always check your appliance labels, your tariff and the manufacturer’s data.
- UK, price cap (26.32p/kWh, Oct–Dec 2026): a car doing 3.5 miles per kWh, charged on a wallbox, costs about £8.05 per 100 miles, or about £644 for 8,000 miles a year.
- US average (18.31¢/kWh, EIA July 2026): a car rated 30 kWh/100 mi costs about $5.88 per 100 miles.
- Your trip computer ignores charging losses: ADAC measured 5–7% on a wallbox and 13–24% on a domestic socket.
- A dedicated EV tariff with a cheap overnight rate is the biggest lever: enter its off-peak rate as your price.
The calculator starts with a car doing 3.5 miles per kWh, 8,000 miles a year, charged on a wallbox at the UK price cap rate. Switch to kWh/100 mi (the unit on US window stickers and fueleconomy.gov) or kWh/100 km if you prefer, and replace the price with your own tariff.
The formula
Charging cost depends on three numbers:
- energy used by the car: distance ÷ miles per kWh (or distance × kWh per mile);
- charging losses: electricity drawn from the grid that never reaches the battery;
- your price per kWh at home.
Cost = energy used × (1 + losses) × price per kWh.
Example (UK): 100 miles ÷ 3.5 mi/kWh = 28.6 kWh in the battery; × 1.07 = 30.6 kWh from the grid; × 26.32p = £8.05.
Cost per 100 miles
For a wallbox (7% losses):
| Car efficiency | Price per kWh | Cost per 100 miles | Cost per year |
|---|---|---|---|
| 3.5 mi/kWh | 26.32p (UK cap) | £8.05 | £644 for 8,000 mi |
| 3.5 mi/kWh | 10p (illustrative off-peak EV rate) | £3.06 | £245 for 8,000 mi |
| 30 kWh/100 mi | 18.31¢ (US average) | $5.88 | $705 for 12,000 mi |
The 10p line is only an illustration: EV tariffs vary by supplier and change often, so type your own off-peak rate into the calculator.
Charging losses: the hidden part of the bill
Some of the electricity you pay for never reaches the battery. It is lost in the on-board charger (which converts AC from the grid into DC for the battery), in the car’s electronics that stay awake while charging, and in cables. The trip computer does not count it.
ADAC, the German automobile club, measured these losses on five recent cars in 2026:
- 11 or 22 kW wallbox: 5.1% to 7.0%;
- reduced-power solar charging (4.1 kW): 8.0% to 12.8%;
- domestic socket (2.3 kW “granny cable”): 12.7% to 24.2%.
The slower the charge, the longer the car’s electronics run and the higher the losses. That is one more reason, after safety and speed, to use a proper home charger.
UK: use an off-peak or EV tariff
Several UK suppliers sell tariffs with a much cheaper overnight rate for EV owners. If you have one, schedule charging (in the car app or charger app) to run inside the cheap window and use that rate in the calculator. Check how the day rate compares with the price cap rate, since daytime use elsewhere in the home may cost more.
US: check time-of-use rates
The US average hides huge differences between states and utilities. Many utilities offer time-of-use or EV rates with cheaper overnight prices. Your bill shows your actual price per kWh, including delivery charges.
Cost of a full charge
For a 60 kWh usable battery, charging from 10% to 80% puts 42 kWh into the battery, about 45 kWh from the grid with wallbox losses: roughly £11.83 at the UK cap rate and $8.23 at the US average. The calculator shows this for the battery size you enter.
Before installing a home charger
- Regular charging from a domestic socket puts a heavy, long load on the circuit: have it checked by an electrician or install a dedicated charger.
- Home chargers should be installed by a qualified electrician.
- Public rapid chargers usually cost much more per kWh than home charging. If you charge away from home part of the time, enter a weighted average price.