How the EV charging cost calculator works
The cost of charging an electric car is the energy you put into the battery multiplied by the price per kilowatt-hour (kWh). The energy is the battery size multiplied by how much of it you fill.
Charging cost = energy added × price per kWh
Cost per mile = price per kWh ÷ miles per kWh
The defaults use the Ofgem price cap electricity rate of 26.32p per kWh for 1 October to 31 December 2026 (Direct Debit, averaged across England, Scotland and Wales), and Zapmap's September 2026 average pay-as-you-go price for rapid and ultra-rapid chargers (50kW and above) of 79p per kWh. Petrol defaults to the UK average of 174.6p a litre from the government's weekly figures for 19 October 2026.
Ofgem notes that the government has removed VAT from household electricity bills between 1 October 2026 and 31 March 2027, so the cap rate doesn't include VAT for that period. The daily standing charge of 54.83p is paid whether you charge or not, so it isn't included here.
Worked example: 60 kWh battery, 20% to 80%
- Energy added: 60 × 60% = 36 kWh
- Home charging: 36 × 26.32p = £9.48
- Public rapid charging: 36 × 79p = £28.44
- Range added at 3.5 miles per kWh: 36 × 3.5 = 126 miles
Per mile that's 7.5p at home and 22.6p on a rapid charger. A petrol car doing 45 mpg at 174.6p a litre costs 17.6p a mile, so the same 126 miles would cost £22.22 in petrol. Over 1,000 miles, home charging costs about £75, petrol about £176 and rapid charging about £226.
Cost per mile at different prices
| Price per kWh | At 3 miles/kWh | At 3.5 miles/kWh | At 4 miles/kWh |
|---|---|---|---|
| 26.32p (price cap) | 8.8p | 7.5p | 6.6p |
| 54p (public fast) | 18.0p | 15.4p | 13.5p |
| 79p (public rapid) | 26.3p | 22.6p | 19.8p |
What efficiency figure should I use?
Most electric cars show average miles per kWh on the dashboard or in their app. Small cars often do 4 miles per kWh or more in mild weather, while large SUVs might manage 2.5 to 3. Efficiency drops in winter because the battery is colder and the heater uses energy, and at sustained motorway speeds. If your car only shows kWh per 100 miles, divide 100 by that figure.
Use the usable battery capacity rather than the gross figure; manufacturers often quote both. Charging from the wall also loses a little energy as heat, so your meter will show slightly more than the battery receives.
Ways to cut charging costs
- Switch to an EV tariff. Many suppliers offer cheap overnight rates for EV owners, often a fraction of the price cap rate. If you can charge mostly at night, this makes the biggest difference.
- Charge to 80% for daily use. Rapid chargers slow down a lot above 80%, so you pay for time as well as energy, and many manufacturers recommend it for battery health.
- Use subscriptions for public charging. Most big networks offer lower per-kWh prices with a monthly subscription, which can pay off if you rapid charge regularly.
- Avoid idle fees. Some networks charge per minute if you stay plugged in after charging finishes.
Comparing running costs with a petrol or diesel car? Use the fuel cost calculator for a journey or the MPG calculator for your real economy. If you're weighing up finance on a new EV, try the car finance calculator.
Frequently asked questions
How much does it cost to charge an electric car at home?
At the Ofgem price cap rate of 26.32p per kWh (October to December 2026), adding 36 kWh to a 60 kWh battery (20% to 80%) costs £9.48. A full charge from empty would cost £15.79.
How much does rapid charging cost in the UK?
Zapmap's average pay-as-you-go price for rapid and ultra-rapid chargers was 79p per kWh in September 2026. A 36 kWh top-up at that price costs £28.44.
Is it cheaper to run an electric car than petrol?
Charging at home usually is. At 26.32p per kWh and 3.5 miles per kWh, an EV costs 7.5p a mile, against 17.6p a mile for a 45 mpg petrol car at 174.6p a litre. Relying on rapid chargers at 79p per kWh costs more than petrol.
How many kWh does it take to charge an electric car?
It depends on the battery size and how much you fill. Charging a 60 kWh battery from 20% to 80% takes 36 kWh, plus a little extra lost as heat during charging.
How much does a full charge cost?
Multiply the usable battery size by the price per kWh. A 75 kWh battery at 26.32p costs £19.74 to charge from empty at home, or £59.25 at 79p on a rapid charger.
Last reviewed October 2026 using 2026/27 figures. This calculator gives an estimate for guidance only.