Use this to compare the annual cost of driving a petrol or diesel car with the cost of driving an electric car.
The calculator uses your annual mileage, fuel price, car economy, electricity price and EV efficiency to estimate the yearly cost of both options, then shows the potential saving from switching to electric.
Further down the page, you’ll also find details on EV tariffs and how cheaper overnight rates can reduce costs even further.
Compare Petrol vs Electric Car Costs
Per year
Fuel: £0 at 0p/mile
Electric: £0 at 0p/mile
Annual Saving: £0 (£0/month)
How to Save with Overnight EV Tariffs
Most of the real savings with an EV don’t come from the car itself. They come from when you charge it.
Time-of-use tariffs like Intelligent Octopus Go and Octopus Go offer much cheaper electricity overnight, when demand is low. Typically you get a 5 to 6 hour window overnight where electricity is a fraction of the daytime rate.
In practice, that can mean something like 7–10p per kWh overnight versus 25–30p per kWh during the day. Charge your car while you sleep, and your cost per mile drops significantly. That’s how people get down to just a few pence per mile.
The key idea is simple: shift your usage. Charging overnight is the big one, but the same principle applies to things like dishwashers, washing machines, or even home batteries if you’ve got one.
If you want the detail, see the following tariffs:
Referral information and free credit offer
If you find Energy Stats UK useful, there are a couple of easy ways to support the site and help cover hosting and server costs.
Thinking about switching energy suppliers?
Homeowners who join Octopus Energy using my referral link get £50 free credit after signing up. Business users get £100 free credit, and if you’re looking at solar or a heat pump, there’s also a £100 gift card through Octopus Tech.
Finally, a £25 gift card can be claimed when having an EV charger installed through Octopus.
“Existing Octopus customer? Find out how you can benefit too. T&Cs apply (only one switching offer per household)”
Or, if you just want to say thanks, you can buy me a coffee.
You can also see more ways to support the site here via the likes of Plusnet broadband, Smarty Mobile, Havenwise remote heat pump control, Hetzner Cloud hosting, Axle Energy, Quidco and more.
If you are thinking about a heat pump, check out my Trusted Heat Pump Installers page along with my guide How to Choose a Heat Pump Installer.
Follow @energystatsuk on Twitter / X, Bluesky and Mastodon for daily tariff graphs and updates.
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Note: The current and past performance of energy pricing is not necessarily a guide to the future.
