EV vs Petrol — cost comparison
Compare the total cost of ownership (TCO) of an electric and a petrol car over your chosen period — purchase price, electricity and fuel, servicing and insurance.
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TCO = purchase price + (energy/fuel + service + insurance) × years. Excludes depreciation and finance cost — estimate those in the lease and depreciation calculators.
How we compare EV and petrol
The calculator adds up total cost of ownership (TCO): the purchase price plus annual running costs multiplied by the comparison period. Energy cost is mileage ÷ 100 × consumption (per 100 km) × price, for both electricity and fuel.
Annual service and insurance are added for each car. The break-even point shows after how many years the cheaper-to-run EV recovers its higher purchase price.
TCO formula
- Energy/fuel cost (year) = mileage ÷ 100 × use × price
- Annual cost = energy/fuel + service + insurance
- TCO = purchase price + annual cost × years
- Break-even = price difference ÷ annual saving
Frequently asked questions
Is an EV really cheaper?
It depends on mileage and energy prices. An EV usually has lower 'fuel' and service costs but a higher purchase price. High annual mileage pays it off faster; with low mileage a petrol car can be cheaper overall.
What about home vs public charging?
Enter an average electricity price per kWh. Home charging is cheaper (e.g. night tariff); public fast chargers cost more — if you use both, use a weighted average.
Does it include depreciation?
Not directly — TCO covers purchase and running costs. Estimate each car's value loss in the depreciation calculator and add it to the comparison.
Is my data sent anywhere?
No — everything is calculated locally in your browser.
Electric vs petrol: when does the EV pay for itself?
Electric cars usually cost more to buy and less to run; petrol cars the reverse. Which wins is therefore a question about your mileage, your electricity price and how long you keep cars — not about ideology. The calculator above compares total cost over your chosen period: purchase price plus energy plus servicing and insurance for each side, using your annual mileage.
The energy arithmetic drives most of the result. An efficient EV uses roughly 0.25–0.30 kWh per mile; a decent petrol car manages 40–50 mpg. What you pay per kWh matters enormously: home charging on an off-peak EV tariff can be several times cheaper than public rapid charging, which can approach petrol cost per mile.
Worked example
Driving 10,000 miles a year: an EV at 0.28 kWh/mile and 30p/kWh costs about £840 a year in electricity; a 45 mpg petrol car at £1.45/litre burns about £1,465 of fuel. Add typically lower EV servicing (no oil, clutch or exhaust; regenerative braking spares the pads) and the running-cost gap is roughly £700–900 a year. If the EV costs £6,000 more to buy, it needs 7–9 years or a home charger with a cheap overnight tariff (which can double the annual saving) to break even — which is precisely the kind of trade-off the calculator makes visible.
What to check before deciding
- Can you charge at home? This is the single biggest factor. Off-peak home tariffs transform EV economics; relying on public rapid chargers can erase the advantage entirely.
- Real-world range vs your real trips. Winter cuts EV range 20–30%. Count your actual long journeys per year — for many households it is a handful, manageable with rapid charging.
- Depreciation cuts both ways. EV resale values have been volatile as new models and price cuts arrive; a used EV bought after the first owner absorbed that drop can be exceptional value.
- Insurance and tyres can be higher for EVs (heavier cars, dearer repairs) — include them in the comparison rather than assuming everything is cheaper.
- Company-car and salary-sacrifice schemes heavily favour EVs in the UK through low benefit-in-kind tax — if you have access, the sums change completely.
Additional questions
How long do EV batteries actually last?
Modern packs are warrantied for 8 years / ~100,000 miles to retain ~70–80% capacity, and real-world degradation data shows most cars comfortably beating that. Battery replacement horror stories are mostly early-generation or accident cases.
Are hybrids the sensible middle ground?
Full hybrids suit high-mileage drivers without home charging — petrol economics with lower fuel use. Plug-in hybrids only pay off if you charge them and most trips fit the electric range; unplugged, they are heavy petrol cars.
What about hydrogen or e-fuels?
For private cars neither is a practical 2026 option in the UK — filling infrastructure is minimal and per-mile costs are far above both petrol and electricity. The realistic comparison for this decade is the one this calculator makes.
Written & fact-checked by Łukasz Wójcik — independent developer, not a licensed financial adviser. Last reviewed: 2026-08-17.
Methodology & assumptions
This estimate is based on the figures and assumptions you enter (purchase price, running costs, mileage, depreciation rate) — actual costs vary by specific vehicle, condition, location and market, and this is not a valuation of any individual vehicle.
Scope & limitations
This calculator is a free, general-purpose estimation tool. It uses simplified assumptions, does not know your full personal or financial circumstances, and is not a substitute for professional financial, tax or legal advice. Figures can change after publication — always check the current rate or threshold at the source below before relying on a result.
Where to check this yourself
Every rate, threshold and rule used above comes from the bodies below. They are the authority; this page is not. Where a figure here disagrees with a source, the source is right — and we would be grateful if you told us. Links go to official government bodies and to registered charities that give free, impartial guidance; none of them pays us and we take no commission.