EV charging cost

There is no such thing as the cost per mile of an EV

Any article that gives you one number has quietly chosen a driver and hidden the choice. The same car, doing the same miles, costs about 2.2p a mile charged overnight on a dedicated EV tariff and about 22p a mile on public rapid.

That is roughly ten times, and against the cheapest verified tariff it is closer to twelve. It is not driving style, not battery health, not tyre pressure. It is whether you have somewhere to plug in at night, and it dwarfs every other variable in the running cost.

The reason it matters so much is that it can flip the decision entirely. For a driver charging at home on an off-peak tariff, fuel is close to a rounding error. For a driver with no off-street parking who relies on rapid chargers, petrol can genuinely be cheaper per mile. Neither of those is "the" EV running cost, and quoting either as if it were is how people end up disappointed.

The rates this is built on, and where each came from

Every figure here was read at its own source in August 2026 rather than recalled, because EV pricing moves quarterly and stale numbers are worse than no numbers.

• Home, dedicated EV tariff: 6.99p a kWh on EDF GoElectric, 8p on Intelligent Octopus Go, 8p on E.ON Next Drive Smart, each inside a fixed nightly window
• Home, general domestic: 26.11p a kWh, the Ofgem price cap for Great Britain for the quarter to 30 September 2026, plus 57.19p a day standing charge
• Public, 50kW and above: 80p a kWh, Zap-Map's weighted average for July 2026
• Public, under 50kW: 54p a kWh, the same index for the slow and fast tier

Note the shape of that list. The gap between the two public tiers is smaller than the gap between the two home ones, which is why moving to an EV tariff is usually the single largest change available to an EV owner's running costs.

HMRC's 7p and 15p, and what each one measures

The Advisory Electricity Rate, used to reimburse company car mileage, is 7p a mile for home charging and 15p for public, from 1 June 2026. Both look reasonable and neither describes either end of the real range. HMRC publishes the inputs, so this is checkable rather than a matter of opinion.

The home figure is built from 26.90p a kWh, the general domestic electricity price, at an assumed 3.59 miles per kWh. That describes somebody charging a car at the same price they boil a kettle. Anybody who has moved to an EV tariff pays roughly a third of that, so the flat rate leaves them substantially ahead.

The public figure is built from the slow and fast index, chargers under 50kW, at 54p a kWh. Almost nobody uses those on a journey. The rapid tier that people actually stop at is a separate published index and it is 80p, so a driver relying on rapid charging is reimbursed well below what the miles cost them.

There is a practical remedy for that second case and it is not well known: where a company car charges in both places, HMRC allows the mileage to be apportioned between the two rates rather than forcing a single blended figure. If most of your charging is public, apportioning is worth the paperwork.

Two things about the public price that a single average hides

The spread across networks is enormous. Across just the top ten rapid networks the price ranged from 59p to 92p a kWh in July 2026. That is nearly 60% variation on identical electricity, so which network you happen to stop at moves your cost more than anything you do behind the wheel. Pay-as-you-go list prices also overstate what people on subscription or membership plans pay.

And the cheap home rate is a window, not a tariff. The off-peak rate applies between fixed hours: 11pm to 6am on EDF GoElectric, 11:30pm to 5:30am on Intelligent Octopus Go, midnight to 6am on E.ON Next Drive Smart. It needs a compatible smart charger and app scheduling to get, and manually overriding the schedule usually puts that charge on the day rate. Being on an EV tariff is not the same as buying every kWh at the EV tariff rate.

Two figures that will not reconcile, so nobody wastes an evening on it

Zap-Map's own per-mile conversion of 16p and 24p implies an efficiency of about 3.3 miles per kWh, slightly below the 3.59 HMRC uses. So figures quoted from the two sources will never agree to the exact penny, and the difference is the efficiency assumption rather than an error in either.

Similarly, HMRC's domestic input of 26.90p a kWh does not match the live Ofgem cap of 26.11p, because the two are recalculated on different cycles from different data. Both are correct on their own terms and they will usually be a few pence apart.

What is not in this and what changes next

This is electricity and petrol, which is one line of a running cost. Insurance, depreciation, servicing, tax and the cost of installing a home charger all sit outside it, and for many drivers depreciation is the largest number of the lot.

Dates worth knowing. The Ofgem cap changes on 1 October 2026, with the next figure published by 26 August. The Advisory Electricity Rate is reviewed quarterly, with the next review due around 1 September. And the cap covers England, Scotland and Wales only: Northern Ireland is regulated separately by the Utility Regulator, so that domestic figure does not apply there. Public charging prices are UK-wide.