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Electric Car vs Petrol Calculator

Updated April 18, 2026 · Major Purchases · Educational use only ·

When does the EV pay back?

Compare electric vs petrol car total cost. Enter prices, mileage, fuel and electricity costs to see break-even and annual savings.

What this tool does

This tool calculates the break-even point of buying an electric vehicle versus a petrol equivalent. Enter EV price, petrol price, annual mileage, petrol fuel cost per litre, and electricity cost per kWh. The calculator shows annual fuel savings, price premium of the EV, break-even in years, and 5-year fuel savings. Assumes 30 mpg for petrol and 4 mi/kWh for EV - adjust expectations for luxury or sporty variants.


Enter Values

Formula Used
EV price
Petrol price
Annual fuel saving

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Disclaimer

Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.

The EV question in 2026

Electric cars have moved from early-adopter territory to mainstream consideration. New EV prices still carry a premium over equivalent petrol cars — typically 3,000 to 8,000 depending on segment — but running costs are dramatically lower. The question for most buyers is not whether EVs are cheaper over the lifetime of ownership, but how many years of ownership it takes to recover the upfront premium.

This calculator compares the two routes using your annual mileage, the price gap, and current fuel and electricity prices that you enter yourself. Prices change — rates are user inputs rather than hardcoded numbers — so the math stays accurate whatever the energy market is doing.

Where EVs save money

Fuel cost per mile. A typical family petrol car at 45 mpg costs around 14 to 16 pence per mile at 1.45/litre. A typical EV driven with mostly home charging at 8 p/kWh (off-peak Octopus Go, Intelligent Octopus) costs around 2 to 3 pence per mile. Even at 28 p/kWh peak rates the per-mile cost is around 7 to 8 pence. Over 10,000 annual miles that is 600 to 1,400 a year in fuel savings.

Servicing and maintenance. EVs have fewer moving parts — no oil, no spark plugs, no timing belt, no clutch, no gearbox oil — so routine servicing runs roughly 30 to 50 per cent cheaper. Brakes last longer because regenerative braking does much of the slowing. Expect 200 to 400 a year savings for a typical EV versus petrol.

Vehicle Excise Duty and benefit-in-kind. EVs currently pay 0 or minimal VED (rules are changing — check current rates). For company car drivers, the BIK rate on EVs is 3 per cent versus 25 to 37 per cent for equivalent petrol cars — that alone can save 2,000 to 6,000 a year in tax on a 50,000 company car.

Where petrol still wins

Purchase price. A Volkswagen Golf starts around 26,000 petrol versus 36,000 for an ID.3 electric equivalent. That 10,000 gap is the headwind EVs must overcome through fuel and maintenance savings.

Depreciation. EV residual values softened through as second-hand EV supply grew and battery fears persisted. Some EVs lost 40 per cent in two years, worse than petrol equivalents. Residual values are stabilising but remain model-dependent.

Long-distance driving. If your mileage is dominated by motorway trips and you cannot charge at home, EV costs rise substantially. Rapid-charger rates of 60 to 85 p/kWh mean the per-mile cost can match or exceed petrol. EVs shine for people who charge at home overnight and drive mostly local or regional.

The break-even math

Take the purchase price gap (EV price minus petrol price) and divide by annual fuel-plus-maintenance savings. The result is years to break even.

Worked example: 10,000 EV premium, 12,000 miles a year, 45 mpg petrol at 1.45/litre, EV at 3 p/mile mostly home charged. Petrol fuel cost: ~1,760 a year. EV fuel cost: ~360 a year. Fuel saving alone: 1,400. Add 300 maintenance savings: 1,700 a year. Break-even: roughly 5.9 years.

At 20,000 miles a year the same math gives break-even in 3.5 years. At 6,000 miles a year it stretches past 10 years — at which point the car is probably being replaced before it has paid back.

The charging question dominates everything

Home charging changes the economics by a factor of 5 to 10. A household with a driveway, a 7 kW charger, and an EV tariff pays around 2-3 p/mile. A household charging exclusively at public rapid chargers pays 15-20 p/mile. The difference across 10,000 miles is 1,200 to 1,700 a year — more than the annual cost of a small petrol car.

Before committing to an EV, confirm: can you install a home charger, what electricity tariff can you get, and is there reasonable public charging near places you regularly visit? If home charging is not possible, run the numbers again at public-charger rates before deciding.

Non-financial factors

Beyond the units: EVs are quieter, torquier, have fewer service visits, and produce no tailpipe emissions. Some cities (ULEZ, CAZ) charge daily fees on older petrol/diesel cars that EVs avoid entirely. EVs also allow Vehicle-to-Load and Vehicle-to-Grid applications that are maturing. Petrol cars have a denser refuelling network, faster refuelling, and — for now — wider second-hand choice.

What the calculator does not include

The model handles fuel cost per mile. It does not include insurance differences (EVs typically cost more to insure), VED, charger installation costs (800-1,200 upfront, partially covered by grants), depreciation, or regional subsidies. For a complete lifetime-cost picture combine this output with separate insurance quotes and an honest depreciation estimate for the specific models you are comparing.

Example Scenario

EV at 35,000 £ vs petrol at 25,000 £ over 10,000 miles miles per year, break-even in 40.0 yrs.

Inputs

EV Purchase Price:35,000 £
Petrol Car Purchase Price:25,000 £
Annual Mileage:10,000 miles
Petrol Cost (per litre):1.5 £
Electricity Cost (per kWh, pence):10 p
Expected Result40.0 yrs

This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.

Sources & Methodology

Methodology

Annual petrol fuel = miles / 30 mpg × petrol price per litre. Annual electric fuel = miles / 4 mi/kWh × electricity per kWh. Annual saving = petrol - electric. Break-even years = price difference / annual saving.

Frequently Asked Questions

Is it actually cheaper to own an electric car than a petrol car?
Over several years, many EV owners find their total costs are lower, largely due to cheaper electricity versus petrol and reduced maintenance bills. However, the answer depends heavily on how much is driven, local energy prices, and the upfront purchase prices involved. This calculator can help illustrate that based on individual numbers.
How long does it take for an electric car to pay for itself compared to petrol?
The break-even point — where cumulative savings offset the higher purchase price — varies widely and is typically somewhere between two and six years for many drivers. Factors like annual mileage, fuel prices, and any government incentives all shift that timeline. This calculator can help illustrate that for a specific situation.
How much cheaper is it to charge an EV than fill up with petrol?
As a rough guide, electricity tends to cost around 60–70% less per mile than petrol, though this depends on local electricity rates and the efficiency of the vehicle. Charging at home overnight is generally the most cost-effective option, while public rapid chargers can narrow that gap considerably. This calculator can help illustrate the difference using actual energy costs.
Do electric cars really have lower maintenance costs?
Generally speaking, EVs have fewer mechanical components than petrol cars — no gearbox, no exhaust system, no oil to change — which tends to reduce routine servicing costs. Many EV owners report maintenance bills that are noticeably lower over time, though tyres and brake fluid still need attention. This calculator can help illustrate how maintenance savings factor into the five-year total cost comparison.
What is the total cost of owning an electric car over 5 years?
The five-year total cost typically includes the purchase price, depreciation, fuel or charging costs, insurance, and servicing — and it varies enormously depending on the model and how the car is used. It is not unusual for the total cost of ownership to look quite different from the upfront price alone once all those elements are added together. This calculator can help illustrate a side-by-side five-year estimate based on the relevant figures.

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