Calculator
EV vs petrol cost calculator (UK): fuel against home and public charging
Rates last checked: 15 October 2026 · SmartShift UK
Put in your miles and your car’s real mpg to compare a year of petrol or diesel against charging an electric car. Pump prices are the government’s UK averages for the week commencing 12 October 2026; electricity rates are the ones on our EV tariff comparison.
Rates last checked: 15 October 2026. Pump prices: UK averages from the Department for Energy Security and Net Zero, week commencing 12 October 2026.
Enter your car’s mpg
- Fuel a year: –
- EV electricity a year: –
Fuel cost = miles ÷ mpg × 4.54609 litres per UK gallon × pump price. EV cost = miles ÷ miles per kWh, grossed up for losses, split between your home rate and the public rate. 3.61 miles per kWh is the median of the 142 cars in EV charging costs by car. 75p/kWh is the site’s illustration of public rapid charging, not a published average. Running costs only: no standing charge, servicing, tax, insurance or purchase price.
Examples at 8,000 miles a year
| A year | Per mile | |
|---|---|---|
| 35 mpg petrol | £1,821 | 22.8p |
| 45 mpg petrol | £1,417 | 17.7p |
| 55 mpg petrol | £1,159 | 14.5p |
| EV at 7.6p (Intelligent Octopus Go) | £168 | 2.1p |
| EV at 26.32p (price cap) | £583 | 7.3p |
| EV at 75p (public rapid illustration) | £1,662 | 20.8p |
The mpg figures are examples, not averages. Running costs only: the car’s price, insurance, tax and servicing aren’t included, and the EV figures leave out standing charges and charging losses.
For a tariff-by-tariff whole bill, use the EV tariff savings calculator. For your exact car, see EV charging costs by car.
Questions people ask
Is an electric car cheaper to run than petrol?
Usually, if you charge at home. At the UK average of 175.28p a litre (week commencing 12 October 2026), a 45 mpg petrol car costs about £1,417 in fuel for 8,000 miles. A typical EV (3.61 mi/kWh) costs about £168 charged at 7.6p, or £583 at the 26.32p price cap. Charged only at public rapid chargers at 75p, it would be about £1,662, more than the petrol car.
What petrol price does the calculator use?
The government’s UK average pump price for the week commencing 12 October 2026: 175.28p a litre for petrol and 200.04p for diesel. You can type your own.
Why do I have to enter my mpg?
Because it varies far more between cars and drivers than any average we could quote. Use the figure from your trip computer or fuel receipts, in UK (imperial) gallons.
Does this include standing charges, tax or servicing?
No. It compares fuel and electricity only. Your standing charge is paid whether or not you have an EV. For the full electricity bill on an EV tariff, use the whole-bill calculator.
Is this financial advice?
No. It’s arithmetic on published prices and your inputs.
Not financial advice. These are worked examples from published prices and your inputs. Check your own quote, bill and the supplier’s or manufacturer’s current terms before you switch or buy anything.
Sources
- DESNZ, weekly road fuel prices (week commencing 12 October 2026)
- DESNZ, weekly road fuel prices CSV (2018 to date)
- SmartShift UK, UK EV tariffs compared (13 tariffs, checked 15 October 2026)
- Ofgem, energy price cap unit rates and standing charges (1 October–31 December 2026)
- Octopus Energy, Intelligent Octopus Go (7.6p, 23:30–05:30, 6 hours smart charging, £50 exit fee, chargers from £949)
- EV-Database, UK real-world consumption list (Wh/mile)
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