EV charging cost calculator
The same mile costs a different amount on every kind of charger. At an assumed 3.5 miles per kWh, the Ofgem-capped domestic rate for Great Britain works out at about 7.52p a mile, Intelligent Octopus Go overnight about 2.17p a mile, and InstaVolt peak public rapid charging about 26.29p a mile, which is dearer per mile than a petrol car returning an assumed 40 mpg at about 19.78p. The Ofgem cap does not apply in Northern Ireland.
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 9,400 miles in 2025 (DfT National Travel Survey). Those mileages are self-estimated by drivers, not measured.
How far the car travels on one unit of electricity. It differs from car to car, and can be lower in cold weather.
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.
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 slider opens at 20% only as a starting point, a figure of ours rather than a published average. 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 £707 a year (7.52p a mile). All of it on the public network costs somewhere between £1,477 and £2,471 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.
On the car’s spec sheet. A typical family electric car is between 50 and 77 kWh.
Charging cost, one year
9.16p to 11.27p 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.
19.78p per mile at the UK average pump price, week commencing 26 October 2026 (DESNZ). Pick a public rate above to compare a single charging figure against it.
The petrol car you are comparing with.
40 mpg is an assumption, not a published average. 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 (54.83p 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, so this is not what owning the car costs. We have no used-car depreciation figure we can source, so we show none.
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.
Browse electric carsThe same car costs roughly 2.17p a mile on Intelligent Octopus Go overnight or 26.29p a mile at InstaVolt peak rapid prices, depending only on where it is plugged in.
That is a spread of about 12.1 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. Both are commercial offers rather than regulated prices: the Intelligent Octopus Go rate was read on its own page on 5 October 2026, and the InstaVolt price was checked on 9 September 2026.
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) | 7.6 | 2.17 | 0% domestic |
| Ofgem capped domestic rate, Great Britain, Direct Debit | 26.32 | 7.52 | excludes VAT while the Great Britain zero rate applies |
| Petrol at an assumed 40 mpg, for comparison | — | 19.78 | Included in the pump price |
| InstaVolt, rapid / ultra-rapid, off-peak (20:00–07:00, app or RFID only) | 55 | 15.71 | 20% standard |
| GRIDSERVE, AC, up to 22kW (Standalone AC units) | 59 | 16.86 | 20% standard |
| GRIDSERVE, DC rapid / ultra-rapid (85–92p depending on site, without membership) | 85–92 | 24.29–26.29 | 20% standard |
| InstaVolt, rapid / ultra-rapid, peak (07:00–20:00) | 92 | 26.29 | 20% standard |
The top row and the InstaVolt peak row are the same car: charging at peak rapid prices costs roughly 12.1 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. Slower and off-peak public charging sits in between: InstaVolt rapid / ultra-rapid, off-peak works out at about 15.71p a mile.
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 26.29p a mile against about 19.78p 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
In Great Britain, domestic electricity is zero-rated for VAT from 1 October 2026 to 30 June 2027; the normal rate is the reduced rate of 5%, which Northern Ireland keeps throughout. Electricity taken from a public charge point is standard-rated at 20%, window or not. 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.
In Charge My Street Ltd v HMRC the First-tier Tribunal held the 5% reduced rate could apply to supplies of up to 1,000 kWh a month, but at Budget 2026 the government announced legislation confirming that electricity from publicly accessible charge points is standard-rated at 20% from 1 November 2026. This page therefore prices public charging at 20%, because that is what you are charged at the plug today. Revenue and Customs Brief 4 (2026).
The Great Britain zero rate is temporary, and is expected to return to 5% after 30 June 2027. Expected, not settled: Budget 2026 extended the window to that date and said nothing about what follows it, and it could be extended again. 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 26.32p and excludes VAT while the Great Britain zero rate applies. HMRC, Revenue and Customs Brief 10 (2026), read on 5 October 2026.
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) sets a maximum average price for Power NI through a price control and a tariff review — a maximum average charge per unit across that one supplier's tariff, rather than Ofgem's cap on the unit rate and standing charge of every licensed supplier in Great Britain. The annual domestic electricity bill the Utility Regulator publishes under it — for a customer using 3,200 kWh a year on the standard tariff, which is the basis that makes the number mean anything — 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 regulated 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.
The 54 pence is narrower than it looks. It is the Zapmap public charging price index for chargers under 50 kW — HMRC's own wording is slow or fast charging, which the Department for Transport now calls Standard and Standard plus — uprated with the latest Office for National Statistics estimate of electricity prices. Rapid and ultra-rapid charging is not in it, which is why the operator rates offered above are so much higher.
Use the price on the unit
You never have to guess a public rate, 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. Why every operator has to post that price, and what the tariffs across the networks currently look like, is set out in our guide to EV charging costs in the UK.
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. The 40 mpg is ours, not a published average. The pump price behind it is the UK average pump price, week commencing 26 October 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 Intelligent Octopus Go rate of 7.6p is Octopus’s own “from” figure, read on its page on 5 October 2026; your own rate comes from a postcode quote.
- 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.
For guidance only, and a model rather than a quotation. Regulated electricity figures verified against Ofgem and the Utility Regulator on 9 September 2026; public operator tariffs checked 9 September 2026; Intelligent Octopus Go read on 5 October 2026; pump price from the UK average pump price, week commencing 26 October 2026 (DESNZ). Ofgem publishes the current cap unit rates and standing charges.
Example · Charging, per year
£861 to £1,060
Example using default figures. Pick a public rate for one figure