EV vs Petrol True Cost Calculator
Don't compare only the price at the pump or the plug — understand the real cost. This weighs depreciation, energy or fuel, insurance, tax and servicing side by side, over however long and however far you actually drive.
Shared assumptions
EV
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Petrol
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What drives the difference?
The biggest cost differences between the two cars:
Energy, fuel and running-cost figures are adjustable defaults, not current live prices — update them to match your own tariff, local fuel prices and quotes for an accurate comparison.
Methodology
Total cost = depreciation (purchase price minus estimated resale value) + energy or fuel + insurance + VED + servicing, tyres and other running costs over the term, plus any finance interest you enter. Energy cost splits your EV's charging between home and public rates using the percentage you set; fuel cost converts your annual mileage and MPG into UK gallons, then litres, at your entered pump price. See the methodology page for the depreciation and finance conventions used across every calculator on this site.
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Frequently asked questions
Why include depreciation when comparing running costs?
Depreciation is usually the single largest cost of owning any car — often larger than fuel or energy. Comparing EVs and petrol cars on running costs alone, without depreciation, gives a misleading picture of which is actually cheaper to own.
Why does the calculator ask for a home charging percentage?
Home charging is typically far cheaper per mile than public rapid charging. Two EV drivers with identical cars can have very different real running costs depending on how much of their charging happens at home versus on the public network — so it materially changes the total.
Are the electricity and petrol prices shown here accurate?
They're editable starting defaults, not live prices. Electricity tariffs, public charging rates and pump prices all vary by location, supplier and time — replace them with your own real figures for an accurate result.
Last reviewed: 30 August 2026. Figures and methodology are reviewed as UK rates and rules change.