The cost of a home charge is straightforward arithmetic: the number of kilowatt-hours (kWh) that go into the battery multiplied by your electricity price per kWh. As a purely illustrative example, if you added 40kWh at a rate of 10p per kWh, that charge would cost £4. Your real rate is on your bill or in your supplier's app, and it varies a lot between standard and EV-specific tariffs.
Two things make the real figure a little higher than the sum suggests. Charging isn't perfectly efficient, so you draw somewhat more from the wall than ends up in the battery, and many people charge at whatever rate applies when they plug in rather than at the cheapest window. Scheduling charging into an overnight off-peak window is the single biggest lever, which is where a smart charger earns its keep.
To turn cost per charge into cost per mile, divide by the miles you gain. Efficient cars can manage roughly three to four miles per kWh, depending on driving conditions, so your cost per mile is your price per kWh divided by that number. Compare that to your petrol or diesel cost per mile and you can see the saving.
Rather than doing the sums yourself, try our free EV Money Calculator. And if you haven't got a home charger yet, tell us about your car and parking in the quote form and we'll help connect you with a suitable installer.
Ready to get started? Get a free quote, or browse popular EV chargers and how installation works for more background. Not sure an EV will save you money? Try our free EV Money Calculator.