Home vs public charging: how to work out the cost
A simple way to compare what a charge costs at home and on the road.
The cost of charging comes down to two numbers: how much energy you put in (kWh) and the price per kWh.
The formula
Cost = kWh added × price per kWh. Adding 40kWh at 10p per kWh costs £4. At 70p per kWh it costs £28. Those prices are only examples, so use your own tariff and the charger's price.
Cost per mile
Most electric cars do 3 to 4 miles per kWh. To find your cost per mile, divide the price per kWh by your car's miles per kWh. At 3.5 miles per kWh, 10p per kWh works out at about 2.9p a mile.
Cutting the cost
- Off-peak EV tariffs for home charging can cut the price per kWh a lot. Compare the latest EV tariffs from energy suppliers.
- Destination charging at supermarkets or work can be cheap or free.
- Rapid charging is convenient on long trips, but it's usually the most expensive way to charge.
Charging losses mean you draw slightly more from the grid than ends up in the battery. Allow about 10% extra for home charging.
Put your own numbers into the EV charging cost calculator to see your cost per mile and per year.