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Tools / Car & Fuel / Electric vs Petrol Calculator

Compare the annual running cost of a petrol or diesel car with an electric vehicle using your own mileage, efficiency, and energy prices.

Press Enter to move to the next field. On the last field, Enter moves to the result.

Enter the number of miles you expect to drive each year.
miles

Petrol or diesel

Use an imperial miles-per-gallon figure that matches your usual driving.
MPG
Enter the forecourt price in pence per litre.
p

Electric vehicle

Miles per kWh is a more useful guide than official range.
mi/kWh
Use your home tariff or charging rate in pence per kWh.
p

EV is cheaper to run

Annual saving with an EV:
£758

Based on 8,000 miles a year, the EV costs about £758 less to run, or roughly £63 a month.

Annual petrol cost£1,318
Annual EV cost£560
Petrol cost per mile£0.16
EV cost per mile£0.07

* The results provided by this calculator are estimations only. Actual figures may vary due to differences in rates or usage. View full disclaimer

Calculated by SmartMoneyTools.co.uk

How the comparison works

The petrol side converts your annual mileage and fuel efficiency into imperial gallons, then into litres using the UK imperial gallon conversion. Those litres are multiplied by your fuel price per litre to estimate the annual spend.

The EV side divides your annual mileage by EV efficiency to estimate annual kWh use, then multiplies that by your electricity price. Both totals are then converted into a yearly saving and a cost-per-mile comparison.

Real-world costs still depend on route, weather, traffic, driving style, and whether you mostly charge at home or on public networks.

Frequently Asked Questions

What electricity price should I use?
For most households, the best starting point is your home unit rate in electricity price. If you mainly charge overnight on an EV tariff, enter that off-peak rate instead. Public rapid charging can cost much more, so this comparison will only be fair if you use a rate that matches how you actually charge.
What is a typical EV efficiency?
A smaller EV can often manage around 4 mi/kWh in mixed driving, while larger SUVs may be closer to 2.5 to 3 mi/kWh. If you already own the car, your trip computer is usually the best guide for the EV efficiency input.
Does this include all running costs?
No. This page compares only the energy cost shown in the headline result. Insurance, servicing, tyres, VED, depreciation, and finance costs are outside the scope of this calculator.
Is it cheaper to charge at home or use public chargers?
Home charging is usually cheaper, especially on off-peak tariffs. Public rapid charging can narrow or even remove the saving. If you want to estimate a home charging bill separately, try the Electricity Bill Calculator.
How does mileage affect the saving?
The comparison scales directly with annual mileage. Higher-mileage drivers feel any difference in cost per mile much more strongly, while lower-mileage drivers will usually see a smaller annual saving.
Tools / Car & Fuel / Electric vs Petrol Calculator