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EV vs Petrol Running Cost Calculator UK

Compare the annual running cost of an electric car against an equivalent petrol car. UK figures with home vs public charging split, Octopus Go tariff presets, and post-2025 VED road tax.

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Interactive EV vs petrol running cost calculator

Worked example

8,000 miles/yr, mid-size EV at 3.8 mi/kWh, 85% charged at home on Octopus Go (8.5p/kWh), vs a 48 MPG petrol car at 145p/litre:

EV annual running cost
£521
Petrol annual running cost
£1444
EV pence per mile
6.5p
Petrol pence per mile
18.0p
Annual saving (EV)
£923
Litres of petrol avoided
758 L

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EV savings multiply on a cheap night tariff

Octopus Go and Intelligent Octopus Go charge EVs at 7–8.5p/kWh — about a fifth the cost of a standard tariff.

Open full EV tariff calculator →

What this calculator models

  • Energy cost. EV kWh × your tariff (split between home and public rates). Petrol litres × pump price.
  • Road tax (VED). £195/yr for both sides — EVs joined the standard rate in April 2025.
  • Service uplift. Petrol cars cost roughly £150/yr more to maintain (oil, belts, clutch, exhaust). Override it if you know your figure.

What v1 doesn't model

  • Depreciation and insurance. Both dwarf running costs but aren't what this page is about.
  • Company-car BIK. Electric company cars are dramatically cheaper via salary sacrifice — a completely different calculation.
  • MOT / tyre wear. Roughly a wash between the two drivetrains.
  • Congestion / ULEZ charges. EVs are exempt — if you drive in central London, add £12.50/day for petrol.

Frequently asked questions

Are the 2025 VED changes included?
Yes. From April 2025, EVs pay the £195/year standard VED rate from year 2 onwards, matching petrol. We use £195 flat for both by default; override if your petrol car is in a higher CO2 band.
What miles per kWh should I use?
Real-world UK averages: small hatch (Corsa-e, Renault Zoe) ~4.2 mi/kWh; mid-size (Model 3, ID.3, MG4) ~3.6–3.9 mi/kWh; large SUV (Model Y, EV6, Enyaq) ~3.0–3.4 mi/kWh; van-based (ID. Buzz) ~2.5–2.8 mi/kWh. Winter figures are ~15–20% lower. For a tariff-by-tariff breakdown of what that costs per mile, run the [EV home charging cost calculator.
Why does the public charger rate matter so much?
Because at 55–80p/kWh, public rapid charging costs roughly the same per mile as petrol — sometimes more. If you can't charge at home, most of the EV running-cost advantage disappears. The 'percent at home' slider makes this explicit. A dynamic tariff can shave your home unit rate further — see the [Octopus Agile savings calculator.
What does the service uplift figure cover?
EVs don't need engine oil changes, cam-belts, clutches or exhausts. Industry surveys (Kwik Fit, RAC) put the annual servicing gap at £100–£200. We default to £150; override with your actual quotes if you have them.
What's left out?
Depreciation, insurance, BIK if it's a company car, ULEZ/congestion charges, and any remaining Electric Vehicle Homecharge Scheme balance (scheme closed for owner-occupiers in 2022; landlords and flats still qualify until 2026). Also out of scope: bill-side hedging against the [Ofgem price cap and the extra saving you unlock if your EV runs on solar — the [solar + battery + EV combined savings calculator models that properly.

How the numbers actually work

The two figures that drive everything are pence per mile. A 3.8 mi/kWh EV on an 8.5p night tariff costs about 2.2p/mile in energy; a 48 MPG petrol car at 145p/litre costs about 13.7p/mile in fuel. That 11p/mile gap — roughly £900 a year at 8,000 miles — is the core of the EV case, and it's why most UK households with off-street parking come out ahead even once road tax is equal.

It falls apart in two places. First, if you can't charge at home, you're paying 50–80p/kWh at public rapids, which is almost identical to petrol in pence per mile. Second, if you drive very few miles (under ~4,000/yr), the fixed costs — VED, service uplift — dominate energy, and the EV advantage shrinks. For the typical UK driver with a driveway, an EV is meaningfully cheaper to run; for a flat-dweller commuting 3k/yr, it's line-ball.

If you're trying to squeeze the most out of an EV, pair it with a time-of-use tariff — see the EV home charging cost calculator for a detailed tariff breakdown, or the Octopus Agile calculator for half-hourly pricing.

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