How much does it cost to charge an electric car?
Charging an EV can be dramatically cheaper than fuelling a petrol car — or surprisingly expensive — depending on where you plug in. The split between cheap home charging and pricey public rapids is the single biggest factor. Here's how to work out your real cost.
Miles per kWh and pence per kWh
EV running cost comes down to two numbers: how far the car goes per kWh (its efficiency, typically 3–4 miles/kWh) and what you pay per kWh. Multiply your annual miles by the cost per mile to get the yearly bill:
Cost per mile = price per kWh ÷ miles per kWh
At 7p/kWh and 3.5 miles/kWh, that's just 2p a mile.
A huge price difference
This is where EV costs diverge wildly:
- Home off-peak: dedicated EV tariffs offer night rates around 7p/kWh — about 2p a mile.
- Home standard: at the 27p cap rate, roughly 8p a mile.
- Public rapid: 60–85p/kWh — around 20p a mile, comparable to or worse than petrol.
When EVs win
A 45 MPG petrol car at £1.40 a litre costs about 14p a mile. An EV charged mostly at home destroys that — but one charged mostly on public rapids may not save much at all. Your home/public split, more than the car itself, decides whether you save.
No home charger changes the sums
9,000 miles, mostly home charging
Driving 9,000 miles a year at 3.5 miles/kWh uses about 2,570 kWh. Charging 80% at home (7p) and 20% on public rapids (75p) costs roughly £530 a year — about 6p a mile. The equivalent petrol car at 45 MPG would cost around £1,270, so the EV saves about £740 a year.
Common EV charging mistakes
- Assuming all charging is cheap. Public rapid charging can cost as much per mile as petrol.
- Not switching to an EV tariff. A dedicated off-peak tariff can cut home charging cost by two-thirds.
- Ignoring winter efficiency. Cold weather and heating can cut range by 20–30%, raising cost per mile.
- Forgetting EV road tax. From April 2025 EVs pay VED, so they are no longer tax-free to keep on the road.