Energy
Start with the energy used
Use the charge you actually added, not the car's full battery size. A part charge is cheaper than a full one.
Costs
What does a home charge cost?
The cost of a charge is the energy you use multiplied by your electricity price. Choose your car and charge levels below, or enter the energy added and the price on your bill.
For the difference between meter energy and battery energy, read charging losses. For tariff windows and other costs, see the home charging cost guide.
Cost calculator
Work out one charging session
Choose your car and tariff, or enter your own energy and electricity price.
Choose your car to see an estimate. If it is not listed, select "Enter your own figures" and enter the energy added and the price on your bill.
The sum
Multiply the electricity used by its price
Multiply the kWh used by your price in pence per kWh to get the cost in pence. Divide by 100 for pounds.
How to work out the cost
Electricity used for charging
kWh used
Your electricity price at that time
pence per kWh
Estimated session cost
total pence
Multiply the electricity used by the price you pay for each kWh. This is an estimate, not a supplier quote. Your meter usually records more electricity than the battery stores.
Before you compare
Three things that affect your charging cost
Change any one of these and the cost changes, even for the same car.
Your rate
Use the price for that time
Use the pence per kWh that applies while the car is charging. An overnight rate only covers that window.
Losses
Allow for electricity the battery does not store
Your meter usually records more electricity than the battery gains. Using the battery gain leaves out charging losses; using the metered electricity used for the charge includes them.
Worked example
A 40 kWh overnight charge
One ordinary top-up, worked out in full, so you can repeat it with your own numbers.
A car adds 40 kWh overnight.
Your tariff charges 25p per kWh at that time.
40 kWh multiplied by 25p is 1,000p.
1,000p is £10.00.
40 kWh at 25p per kWh is £10.00
In plain English: you pay for the energy you put into the car, and you pay your unit rate for every kWh of it. If your car took a bit more from the grid than 40 kWh, the true cost is slightly higher. If you charge 40 kWh every week, that is about £43 a month at the same rate, before any standing charge.