How much does it cost to charge an electric car? Less than petrol — usually a lot less — but the real answer depends on where you charge, your electricity tariff, and how efficient your car is. This calculator blends it all together: your mileage, home vs public charging split, and tariffs, then shows you the honest per-mile cost next to a petrol equivalent.
Your driving
Most EVs do 3–4 miles per kWh. Check your car's trip computer or manual.
Where you charge
Tip: EV-specific overnight tariffs can be under 10p/kWh — see below.
Petrol comparison
Your annual charging cost
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Cost per mile
You save vs petrol
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Illustration only, based on the figures you enter. Real costs vary with driving style, weather, charger efficiency and tariff changes.
How the calculation works
Tell it your annual mileage and your car’s efficiency (miles per kWh — most EVs manage 3–4). Then split your charging between home and public, set your tariffs, and add a petrol car to compare against. It works out the electricity you’ll use in a year, what each chunk costs, and the saving versus petrol.
Home charging vs public charging
Home charging is where EVs win big. On a standard tariff (around 24.5p/kWh) a typical EV costs roughly 7p a mile. On an EV-specific overnight tariff (often under 10p/kWh) that can drop to 2–3p a mile. Public chargers cost far more — about 45p/kWh for slow chargers, 65p for fast, and 80p or more for rapid — which is why the calculator lets you set the split. Someone charging 80% at home pays a fraction of someone relying on rapids.
EV electricity tariffs
Several UK suppliers offer tariffs with cheap overnight rates for EV owners — Octopus Intelligent Go is the best-known, at around 7p/kWh overnight. You usually need a smart meter and a compatible charger or car. If you drive an EV and charge at home, not being on one of these tariffs is leaving money on the table.
What affects your efficiency
That 3.5 miles per kWh is a fair-weather figure. Cold weather can knock 20–30% off your range, motorway speeds hurt more than town driving, and short winter trips are the worst of all. If most of your driving is winter motorway miles, set efficiency nearer 2.8–3.0 for an honest number.
Charging cost FAQs
How much does it cost to charge an EV at home in the UK?
On a standard tariff of around 24.5p/kWh, a typical EV doing 3.5 miles per kWh costs about 7p a mile — roughly £560 a year for 8,000 miles. On a cheap overnight EV tariff of around 7p/kWh, the same driving costs about 2p a mile, or £160 a year.
Is charging an EV cheaper than petrol?
Almost always, if you charge at home. At 9–10p a mile for home charging versus 14–16p a mile for petrol, a typical driver saves £400–£800 a year. It flips if you rely on expensive rapid chargers for most of your miles.
What is an EV tariff?
A special electricity tariff with very cheap overnight rates (often under 10p/kWh) for EV owners who charge at home. You usually need a smart meter and a compatible charger or car.
How many kWh does an EV use per year?
Divide your annual mileage by your car’s efficiency. 8,000 miles at 3.5 miles per kWh is about 2,285 kWh a year.
Does cold weather affect charging costs?
It affects efficiency rather than the tariff — you’ll use more kWh for the same miles in winter, so costs rise by roughly 20–30% in the coldest months.
Related: our Car Finance Calculator if you’re buying electric on finance, the ULEZ checker to confirm your EV is exempt, and our guide to whether electric cars pay road tax.
What to check next
Thinking electric? A few more checks before you decide.