The EV Calculator: EV vs Petrol Running Costs UK
Compare electric car vs petrol or diesel running costs, depreciation, charging and insurance. Calculate total EV running costs over 1, 3 or 5 years using your actual mileage and electricity tariff. Works for any vehicle type including electric SUVs, hatchbacks, crossovers and estates. Enter your car prices to see your exact monthly and total cost of ownership.
Weighing an EV against a petrol or diesel car, whether you own it or are comparing two Autotrader listings? Use the first. Already decided on electric and want the total cost, or want to put two EVs head to head? Use the second.
The car you're replacing or comparing against
Petrol insurance, servicing & tax
Compare like with like. A trade-in offer here against a dealer price for the EV will flatter the EV by several hundred pounds. Use retail against retail, or private-sale against private-sale.
Figures are typical real-world mixed driving. Check your own trip computer if you can.
Most EVs: 3-4 miles/kWh in real-world mixed driving
These have the biggest impact on the verdict - set carefully.
What the petrol car would have lost if you'd kept it (an opportunity cost)
Public rapid charging
Share of all charging - home off-peak: 70% · home peak: 30% · public: 0%
EV insurance, servicing & tax
Road pricing & clean air zones
London CC daily commuters: ~£1,620/yr · ULEZ: £12.50/day × days driven
Running costs only - fuel, insurance, tax, servicing
Enter your figures to see the verdictTrue cost - after depreciation and the charger
Enter your figures to see the verdictDepreciation is the hardest number to predict and usually the one that decides the answer. Tap a rate to use it.
Everything you will have spent by each point, including depreciation. Where the lines cross is the real break-even.
| Per month | Petrol | EV |
|---|---|---|
| Fuel / charging | - | - |
| Insurance | - | - |
| Road tax | - | - |
| Servicing | - | - |
| Finance payment | - | - |
| eVED road pricing (3p/mile) | - | - |
| Clean air zone saving | - | - |
| Total per month | - | - |
| Fuel / charging per mile | - | - |
Monthly saving switching to EV
-EV value lost to depreciation
-Petrol would have lost (if kept)
-Depreciation difference
-Total running savings over period
-EV price
-Petrol car value (sold, or not spent)
-Home charger
-Net cash outlay on day one
-Running savings repay the extra cash in
-This section is cash flow, not the cost of switching. The price gap is not money burned, because you still own a car at the end. The verdict at the top uses depreciation instead, Break-even here counts running savings against cash only. The chart above shows the total-cost crossover, which also credits the car you still own.
EV 1 charging
-EV 2 charging
-EV 1 insurance
-EV 2 insurance
-EV 1 servicing
-EV 2 servicing
-Monthly cost difference
-EV 1 total cost
-EV 2 total cost
-Depreciation difference
-Which EV wins overall?
-How this calculator works
This calculator models the complete financial picture of EV ownership across three areas: monthly running costs, upfront outlay, and depreciation over your intended ownership period. It works for any electric vehicle - SUVs, hatchbacks, crossovers, estates - and any petrol or diesel car you are comparing against.
To calculate total EV running costs over 1, 3 or 5 years, set your ownership period using the preset buttons, enter your annual mileage, your electricity tariff rate, and your car prices. The calculator handles everything else and updates the results live as you type.
Running costs
Running costs cover four categories for each car: fuel or charging, insurance, road tax (VED), and servicing. The monthly fuel cost for a petrol car is calculated by converting your annual mileage to litres using your MPG figure (1 gallon = 4.546 litres) and multiplying by the fuel price per litre.
Monthly kWh = (monthly miles ÷ efficiency)
Blended rate = (night rate × off-peak home %) + (day rate × peak home %) + (public rate × public %)
Monthly charging cost = monthly kWh × blended rate
How electric car depreciation is calculated
Depreciation uses a compound annual rate applied to the purchase price. If you buy a car for £14,000 at 15%/year, after 3 years its residual value is £14,000 × (1 - 0.15)³ = £8,574, meaning you've lost £5,426. You can set the depreciation rate manually or use the Low, Typical, High presets as a starting point.
In the Should I switch to an EV? mode, the petrol car depreciation shows what it would have lost had you kept it, an opportunity cost view that makes the comparison fair whether you own the petrol car or are comparing two Autotrader listings. The depreciation difference between the two cars is one of the most important figures in the results, and it is worth modelling a few scenarios using the presets.
The two verdicts, and why they differ
The first verdict covers running costs only: fuel or charging, insurance, road tax and servicing. It is the figure most EV comparisons stop at, and it is usually the flattering one.
The second is the true cost, and it is the number that actually answers the question. It takes the running saving and subtracts two things the first figure ignores: the difference in how much value each car loses over the period, and the cost of a home charger if you need one. On a used EV the depreciation gap is frequently larger than the entire running saving, which is why a car that is cheaper to run can still be more expensive to own.
A common mistake in EV comparisons is to charge the buyer the full price gap between the two cars instead. That treats the purchase price as money burned, when in reality you still own a car at the end of the period. Capital cost belongs in the calculation as depreciation, not as the sticker price.
Running saving = (petrol running costs − EV running costs) × months owned
Depreciation gap = (EV price − EV residual) − (petrol value − petrol residual)
True cost benefit = running saving − depreciation gap − home charger
One field, two situations
The petrol car figure works whether you already own the car or are choosing between two listings, because both come down to the same comparison. If you own it, the money you get for selling it cancels against the value you were already holding. If you are buying it, the money you spend is that same amount. Either way what remains on each side is depreciation, which is why the verdict is identical in both readings.
The one thing to watch is which valuation you use. A part-exchange offer, a private sale price and a dealer asking price for the same car can differ by thousands. Entering a trade-in offer for the petrol car while using a dealer's asking price for the EV compares two different bases and quietly flatters the EV. Use the same kind of figure on both sides.
Why a more expensive petrol car makes the EV look better
This one surprises people, but it is correct. The calculator does not treat a car's price as money spent, it treats the value it loses as money spent. A £12,000 petrol car depreciating at 10% a year loses about £3,250 over three years. An £8,000 one loses about £2,170. So the more expensive petrol car burns roughly £1,080 more of your money over the same period, which narrows the gap to the EV.
The same logic holds whether you already own the petrol car or are choosing between two listings. If you own it, a higher value means more to lose by keeping it and more to put towards the EV. If you are buying either car outright, the pricier petrol option simply costs you more to own. Either way the comparison is between two depreciating assets, not between two price tags.
UK VED rates 2026/27
| Vehicle type | Standard rate | Luxury threshold | Supplement |
|---|---|---|---|
| Petrol / diesel | £200/year | List price > £40,000 | +£440/yr (up to 5 years) |
| Electric (post Apr 2017) | £200/year | List price > £50,000 | +£440/yr (up to 5 years) |
| Electric (pre Apr 2017) | Varies - enter manually | N/A | N/A |
Finance (HP and PCP)
| Finance type | How total cost is calculated | Residual credited? |
|---|---|---|
| Cash | Purchase price + running costs + charger − residual value | Yes - you own it |
| HP | Deposit + (monthly × term) + running + charger − residual value | Yes - you own it at the end |
| PCP (handing back) | Deposit + (monthly × term) + running + charger | No - lender bears residual risk |
All figures are estimates. Depreciation rates vary significantly by model, age, condition and market conditions. This calculator does not constitute financial advice.
About The EV Calculator
The EV Calculator shows the true cost of EV ownership, including depreciation, electricity tariffs, charging costs, insurance, servicing, road tax, and the 2025 EV VED rates. Calculate total ownership costs over 1, 3, 5 or more years using your real electricity tariff, home vs public charging split, and expected mileage. Unlike basic EV cost calculators, it goes beyond fuel savings to model the full financial picture.
What makes it different
You can model your exact charging setup, setting separate day and night rates and choosing what proportion of charging you do off-peak. Enter a cheap overnight tariff like Octopus Go and watch the numbers change instantly. Public charging costs are modelled separately so high-mileage commuters and those without home charging get an accurate picture rather than a flattering one.
Depreciation is included because it is often the biggest cost nobody talks about. Used EV values have fallen sharply in recent years and ignoring that gives a misleading result. The calculator lets you set Low, Typical, High and Very High depreciation presets for both the EV and the petrol car, so you can stress-test the verdict rather than just accepting a headline saving.
Two questions, one tool
Use Should I switch to an EV? to compare two specific cars side by side, whether you are on Autotrader choosing between options or already own the petrol car and want to know if switching makes sense. Use What will this EV cost me? to calculate total cost of ownership for cash, HP or PCP purchases, or to put two EVs head to head on efficiency, depreciation and overall cost. It works for any vehicle type including electric SUVs, hatchbacks, crossovers and estates.
No sign-up required, no accounts, no cookies and no cross-site tracking. Every calculation runs locally in your browser and nothing you enter is sent anywhere, as set out in the privacy policy. Built and maintained in the UK. If you spot an error or have a suggestion, get in touch.
Frequently Asked Questions
How much cheaper is an EV to run than a petrol car in the UK?
On average, EVs cost around 3-5p per mile to charge at home on an off-peak tariff, versus 15-17p per mile for a typical petrol car returning 40-45 MPG at £1.50 a litre. At 10,000 miles per year this can mean fuel savings of £1,000-£1,400 before accounting for lower servicing costs. Use the calculator with your own mileage and tariff for a personalised figure.
Is it worth buying a used EV in the UK?
It depends on your mileage, charging setup, and the price gap between the used EV and your current car. Higher-mileage drivers with home charging and an off-peak tariff typically see the strongest savings. However, depreciation and insurance costs can offset running cost savings on low-mileage use. We go through the full numbers in our guide to buying a used EV in the UK.
How much does it cost to charge an electric car at home in the UK?
At a standard rate of 24-30p/kWh, a typical EV costs around 6-8p per mile. On an off-peak EV tariff such as Octopus Go (~7p/kWh overnight) this drops to around 2p per mile, a significant saving over petrol. The calculator lets you set separate day and night rates and choose what proportion of your charging you do off-peak.
Do EVs qualify for the OZEV home charger grant?
The OZEV grant provides £350 off a home EV charger for eligible homeowners and flat owners with off-street parking. It is applied at point of purchase through an OZEV-approved installer. Tick the grant checkbox in this calculator to factor it into your upfront costs.
Are electric cars exempt from UK clean air zone charges?
Most UK Clean Air Zones still exempt zero-emission vehicles. The London Congestion Charge 100% EV discount ended in December 2025 for new registrations. Always check the specific rules for your local zone.
Do electric cars pay a per-mile road tax in the UK?
It is confirmed. Electric Vehicle Excise Duty (eVED) starts on 1 April 2028 at 3p per mile for battery electric cars and 1.5p for plug-in hybrids, charged on top of standard road tax and rising with inflation from 2029/30. It applies to existing EVs, not just new ones. At 10,000 miles a year that is £300. Ticking the road pricing checkbox adds it to your results, and there is a full breakdown in our guide to the pay-per-mile EV tax.
How accurate are the depreciation figures?
Depreciation is the hardest figure to predict precisely. Used EV depreciation has been notably steep in recent years, and rates of 20-30%/year are not unusual on some models. We recommend modelling a range of rates using the preset buttons to understand the sensitivity of the result.
Can I use this to compare an electric SUV against a petrol SUV?
Yes. The calculator works for any vehicle type - electric SUVs, petrol SUVs, hatchbacks, crossovers or estates. Just enter the asking prices, your mileage, the petrol car's MPG and the EV's efficiency. For a typical electric SUV in mixed driving, efficiency is usually 3.0-3.8 miles per kWh. There is a full worked example in our breakdown of electric SUV running costs in the UK.
How do I calculate total running costs for an EV over 3 years?
Set the ownership period to 3 years using the preset button in the Ownership and Depreciation section. Then enter your annual mileage, electricity tariff rates, insurance, servicing, road tax and the car's purchase price. The calculator will show your total running costs over the full 3-year period including depreciation, and compare them against a petrol car if you are using the Should I switch to an EV? mode.
How do I work out the total cost of ownership for an electric car including depreciation?
Use the What will this EV cost me? mode and set your ownership period. Enter the purchase price, your annual mileage, electricity tariff, insurance and servicing costs, and your expected depreciation rate. The calculator adds up all running costs over the period and subtracts the estimated residual value to give you the true total cost of ownership, not just the monthly payment.
Can I compare monthly running costs for a specific mileage - for example 1,200 miles a month?
Yes. Enter 14,400 in the annual miles field (1,200 × 12) and the calculator will show monthly costs based on that mileage. All results including fuel or charging, insurance, servicing and road tax are broken down monthly as well as over your full ownership period.
How does electric car depreciation compare to petrol car depreciation?
Used EVs have generally depreciated faster than equivalent petrol cars over 2023-2025 as supply increased. Typical used EV depreciation rates are 15-25%/year depending on the model, versus 8-15%/year for mainstream petrol cars. However, this varies significantly by model - Teslas and some Korean EVs hold value better than Chinese-brand or older models. Use the depreciation presets in the calculator to model different scenarios and see how much the difference in depreciation affects the overall result.