Reviewed by Mustafa Bilgic
Founder, WebCalculator
Home electricity rate default is the Ofgem Q3 2026 price cap (26.11p/kWh). Public charging and petrol prices are user-adjustable. Not financial advice.
This EV charging cost calculator compares the annual fuel cost of an electric vehicle charged at home or at public chargers against a petrol or diesel car. Enter your annual mileage, electricity rate and fuel price to see the difference in pence per mile and total cost per year.
Home, public & petrol side by side
The key metric is cost per mile. Electric vehicles are far more efficient than combustion engines — converting roughly 85% of electrical energy into motion versus 25-30% for petrol. Combined with cheaper "fuel", this makes EVs substantially less expensive to run mile for mile.
However, the where you charge matters enormously. Home charging at the standard Ofgem cap rate is roughly a third of petrol cost per mile. Public rapid charging on motorways can be more than double the home rate, narrowing the saving. Off-peak EV tariffs (7-9p/kWh overnight) cut home charging costs further still.
| Method | Rate | Cost per mile* |
|---|---|---|
| Home (Ofgem cap Q3 2026) | 26.11p/kWh | ~7.5p |
| Home (off-peak EV tariff) | ~8p/kWh | ~2.3p |
| Public slow (7-22kW) | 35-45p/kWh | ~10-13p |
| Public rapid (50kW+) | 50-79p/kWh | ~14-23p |
| Petrol (40mpg @ 140p/litre) | — | ~16p |
*Based on 3.5 miles/kWh average EV efficiency. Ofgem cap: ofgem.gov.uk.
EV home charging: 8,000 / 3.5 = 2,286 kWh x 26.11p = £597/year (7.5p/mile)
EV public rapid: 2,286 kWh x 65p = £1,486/year (18.6p/mile)
Petrol (40mpg): 8,000 / 40 = 200 gallons = 909 litres x £1.40 = £1,273/year (15.9p/mile)
Annual saving (home EV vs petrol): £676
On an off-peak EV tariff at 8p/kWh, that same 8,000 miles would cost just £183/year — saving £1,090 versus petrol. Over a typical 5-year ownership period, the fuel saving alone is £3,380 to £5,450.
Off-peak tariffs. EV-specific energy tariffs offer overnight rates of 7-9p/kWh (versus the standard ~26p). Set your wallbox timer to charge between midnight and 5am. Over 8,000 miles this saves £400+ per year compared to standard rate charging.
Solar panels. With a 4kWp solar system you can charge your EV for free during daylight hours. At 3.5 miles/kWh, the system's 3,600 kWh annual output covers roughly 12,600 miles of driving. See the solar panel payback calculator for the investment case.
Workplace charging. Many employers offer free or subsidised workplace charging. This is not a taxable benefit in kind (exempt until April 2025, check current status) and can eliminate your home charging cost entirely if you commute by EV.
A dedicated 7kW home wallbox costs £800 to £1,200 installed. While you can charge from a standard 3-pin plug (2.3kW), it is slow (12+ hours for a full charge) and puts strain on the socket over time. A wallbox is safer, 3 times faster, and can be set to charge only during off-peak hours. Smart wallboxes also integrate with solar panels, automatically using surplus generation before drawing from the grid.
The OZEV home charger grant has closed to most homeowners but remains available for renters and flat-dwellers. Check gov.uk for the latest eligibility criteria.
The car running cost calculator covers all ownership costs including insurance, road tax and depreciation. Use the mileage allowance calculator to claim AMAP on business miles, and check the vehicle excise duty calculator for your car's road tax band.
At the Ofgem Q3 2026 price cap rate of 26.11p per kWh, charging a typical 60 kWh EV battery from empty to full at home costs about £15.67. With an average efficiency of 3.5 miles per kWh, that gives a cost of roughly 7.5p per mile — about a third of the fuel cost for a comparable petrol car.
Public charging costs vary widely. Slow chargers at supermarkets may be free or 30p to 40p per kWh. Rapid chargers on motorways and forecourts typically cost 50p to 79p per kWh. Ultra-rapid chargers from networks like Ionity can cost 69p to 79p per kWh without a subscription. A full charge at 65p per kWh costs about £39 for a 60 kWh battery.
Yes, significantly cheaper when charging at home. Home charging at 26.11p per kWh costs roughly 7 to 8p per mile for a typical EV. A petrol car averaging 40 mpg at 140p per litre costs about 16p per mile — roughly double. Public rapid charging narrows the gap but is still usually cheaper than petrol.
A home 7kW wallbox charges a 60 kWh battery from 20% to 80% in about 5 to 6 hours, ideal for overnight. A 50kW rapid charger does the same in about 45 minutes. A 150kW ultra-rapid charger can add 100 miles of range in 15 to 20 minutes. Charging speed also depends on the car's maximum charge rate and battery temperature.
Domestic electricity is subject to 5% VAT, not the standard 20%. This applies to home EV charging because it is part of your household electricity supply. Public chargers charge 20% VAT. This VAT difference is one reason home charging is significantly cheaper per kWh.
Yes. If you have a home solar panel system, you can charge your EV for free during daylight hours when the panels are generating. A 4kWp system generates about 3,600 kWh per year — enough to cover roughly 12,000 miles of driving. Smart chargers can be set to use only surplus solar power.
The cheapest option is home charging on an off-peak electricity tariff. EV-specific tariffs like Octopus Go or OVO Charge Anytime offer overnight rates of 7p to 9p per kWh, bringing the per-mile cost below 3p. Solar charging is even cheaper if you already have panels installed. Public slow chargers at free locations are the cheapest away-from-home option.