EV charging cost calculator
What it costs to charge an electric car in the UK depends almost entirely on where you plug it in: at an assumed 3.5 miles per kWh, the Ofgem-capped domestic rate for Great Britain works out at about 7.5p a mile, Intelligent Octopus Go overnight about 2.3p a mile, and InstaVolt peak public rapid charging about 26.3p a mile, which is dearer per mile than a petrol car returning an assumed 40 mpg at about 18.4p. The Ofgem cap does not apply in Northern Ireland.
The same car costs roughly 2.3p a mile on Intelligent Octopus Go overnight or 26.3p a mile at InstaVolt peak rapid prices, depending only on where it is plugged in.
That is a spread of about 11.4 times on identical miles. The cheap end needs a domestic supply and a smart meter, so a driver with no off-street parking cannot reach it, and the expensive end costs more per mile than petrol. Both figures use the DfT assumption of 3.5 miles per kWh, and both are commercial offers checked on 9 September 2026 rather than regulated prices.
Can you charge at home?
This decides more than the car does. A domestic off-peak tariff needs a home supply, a smart meter and an eligible car or charger.
Your driving
Battery electric cars in England averaged 8,900 miles in 2024 (DfT National Travel Survey). Those mileages are self-estimated by drivers, not measured.
The default of 3.5 is an assumption, not your car: DfT assumption for a 70–80 kWh battery, including charging losses. Charging losses matter here, because you pay for what goes into the wall rather than what reaches the battery. Put your own trip-computer figure in if you have one, and expect it to fall in winter.
Where you charge
Home rate
Your bill or your supplier app gives the exact figure. The Ofgem cap is a Great Britain average of regional caps, so your own rate will differ, and it does not apply in Northern Ireland at all.
Public rate
Nothing is pre-selected, because operator prices are commercial offers rather than regulated rates. Pick the one you actually use, or type the price from the charge point itself. Until you do, the result below is shown as a range.
Under the Public Charge Point Regulations 2023 every public charge point must display its price in pence per kWh, so you can always check before plugging in. The operator prices above were checked on 9 September 2026 and change without notice.
The slider opens at 20% only as a starting point. No UK body publishes an average home/public charging split, so set it to your own pattern.
This slider moves the answer more than the choice of car does.
All of it at Ofgem capped domestic rate costs about £664 a year (7.5p a mile). All of it on the public network costs somewhere between £1,399 and £2,339 a year across the operator prices listed above. Same car, same miles.
Cost of one charge (optional)
Enter the usable battery size from the car's specification if you want the cost of filling it from empty.
Charging cost, one year
9.1p to 11.2p per mile. The range is the listed operator prices, from InstaVolt rapid / ultra-rapid, off-peak to InstaVolt rapid / ultra-rapid, peak. Choose a public rate, or type the one on the charge point, for a single figure.
18.4p per mile at the UK average pump price, week commencing 31 August 2026 (DESNZ). Pick a public rate above to compare a single charging figure against it.
40 mpg is an assumption, not a published average. No UK body publishes a real-world MPG figure, so use what your own car returns.
This is a model, not your bill. It runs on an assumed efficiency and the rate you selected, and it excludes the daily standing charge (57.19p a day under the current cap), which you pay whether or not you charge a car.
What this leaves out
Electricity only. Vehicle tax, insurance, tyres, servicing and depreciation are all excluded, and over a few years they matter more than charging does. No UK public body publishes used-car depreciation, so no page can honestly put a figure on the largest single cost of ownership.
For a whole-car comparison that includes vehicle tax, use the EV vs petrol running cost calculator, and check a specific car's tax with the car tax calculator.
Where you charge is the whole answer
Every rate below moves the same car over the same miles. At the DfT assumption of 3.5 miles per kWh, the pence-per-mile column is what the electricity alone would cost you.
| Where you charge | Pence per kWh | Pence per mile | VAT |
|---|---|---|---|
| Intelligent Octopus Go, home overnight (23:30–05:30) | 8 | 2.3 | 5% domestic |
| Ofgem capped domestic rate, Great Britain, Direct Debit | 26.11 | 7.5 | includes VAT at 5% |
| Petrol at an assumed 40 mpg, for comparison | — | 18.4 | Included in the pump price |
| InstaVolt, rapid / ultra-rapid, off-peak (20:00–07:00, app or RFID only) | 55 | 15.7 | 20% standard |
| GRIDSERVE, AC, up to 22kW (Standalone AC units) | 59 | 16.9 | 20% standard |
| GRIDSERVE, DC rapid / ultra-rapid (85–92p depending on site, app price) | 85–92 | 24.3–26.3 | 20% standard |
| InstaVolt, rapid / ultra-rapid, peak (07:00–20:00) | 92 | 26.3 | 20% standard |
Read that table the way it is meant. The top row and the InstaVolt peak row are the same car: charging at peak rapid prices costs roughly 11.4 times what charging on Intelligent Octopus Go overnight costs, and more per mile than petrol at an assumed 40 mpg. Measured against the Ofgem capped domestic rate instead of that off-peak tariff the multiple is about 3.5 times, which is the comparison to use if you are on a standard variable tariff. That is the finding most charging calculators bury. At operator prices, public rapid charging is dearer per mile than petrol. Slower and off-peak public charging sits in between: InstaVolt rapid / ultra-rapid, off-peak works out at about 15.7p a mile.
Operator prices are commercial offers, not regulated rates. They were checked on 9 September 2026 and can change on any day, in either direction, without notice. The petrol column uses the DESNZ weekly UK average pump price.
No off-street parking means no overnight tariff
A smart overnight tariff such as Intelligent Octopus Go needs a smart meter and an eligible car or charger on a domestic supply. If you park on the street you cannot buy that rate at any price, so the cheapest number in every electric car advertisement is not available to you. The realistic comparison for a driver without a driveway is public charging against petrol, not overnight charging against petrol, and at peak rapid prices that comparison runs the other way: about 26.3p a mile against about 18.4p at an assumed 40 mpg.
That does not make an electric car the wrong choice. It moves the case for one onto things this page does not cost, including servicing, the driving itself, local air quality and the clean air zone charges an electric car does not pay. It does mean the running-cost saving quoted in most places is not the saving you would get.
The VAT split between home and public charging
Domestic electricity is charged at the reduced VAT rate of 5%. Electricity taken from a public charge point is standard-rated at 20%. The same kWh therefore carries a different amount of tax depending on where you take it, and the tax difference runs in the same direction as the price difference, widening the gap rather than narrowing it.
On top of that, domestic electricity in Great Britain is temporarily zero-rated for VAT from 1 October 2026 to 31 March 2027, reverting to 5% afterwards. That is why two Ofgem cap figures either side of that date cannot be compared directly: one includes VAT and the other does not, and Ofgem says so itself. The capped rate used on this page is 26.11p and includes VAT at 5%.
Great Britain and Northern Ireland are not the same
The Ofgem price cap covers Great Britain only. It does not apply in Northern Ireland, so the capped figure on this page should not be used for a Northern Ireland home supply. There, the Utility Regulator (UREGNI) approves Power NI's regulated domestic tariff, which is an approved tariff rather than a cap or a maximum, and a typical credit customer's annual domestic electricity bill under it is about £1,093.
VAT on domestic electricity in Northern Ireland stays at 5%, because the temporary Great Britain zero rate does not extend there. If your supply is in Northern Ireland, take the unit price off your own bill and type it into the home rate box above, because that is the only figure that will be right for you. The Utility Regulator publishes the approved tariff.
The HMRC Advisory Electricity Rate is not a private motorist's cost
From 1 September 2026 the Advisory Electricity Rate is 7p a mile for home charging and 15p a mile for public charging. It is the amount an employer may reimburse for business mileage in a company electric car without a tax charge arising. It is a reimbursement convention, not a measurement of what charging costs you, and treating it as your running cost is a category error.
HMRC states the assumptions behind it: 3.59 miles per kWh, 24.47 pence per kWh at home and 54 pence per kWh in public. Change any one of those and the rate stops describing your case. HMRC reviews the figure on 1 March, 1 June, 1 September, 1 December.
Every public charge point has to show its price
Under the Public Charge Point Regulations 2023 every public charge point covered by them must display its price in pence per kWh. You never have to guess, and you never have to take a figure from a comparison page over the one on the unit in front of you. Take the displayed price, put it in the public rate box above, and the answer is yours rather than an average.
What this calculator assumes
- Efficiency is an assumption. The default of 3.5 miles per kWh is the DfT figure for a 70–80 kWh battery and includes charging losses. Real consumption varies with speed, temperature, load and tyres, so your own figure beats any default here.
- The petrol comparison is an assumption. No UK body publishes an average real-world MPG, so 40 mpg is a stated assumption you should replace with your own car's figure. The pump price behind it is the UK average pump price, week commencing 31 August 2026 (DESNZ).
- Standing charges are excluded. You pay the daily standing charge whether or not you own a car, so including it would overstate what charging costs.
- Operator prices move. The public rates offered here are commercial offers checked on 9 September 2026, not regulated prices, and different sites on the same network can differ.
- The capped rate is a Great Britain average. Ofgem caps an average of regional rates for a Direct Debit customer, so your own unit rate will not match it exactly, and it does not apply in Northern Ireland.
For guidance only, and a model rather than a quotation. Regulated electricity figures verified against Ofgem and the Utility Regulator on 9 September 2026; operator tariffs checked 9 September 2026; pump price from the UK average pump price, week commencing 31 August 2026 (DESNZ). Ofgem publishes the current cap unit rates and standing charges.