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Electric Car vs Diesel Running Cost Calculator

Compare the running costs of an electric car against a diesel car using current UK diesel prices and electricity rates. Enter your own mileage, fuel consumption, and charging habits to see the true difference.

Calculator mode

Your driving details

Used for local fuel price lookup. Calculations still work without it.

miles/yr
MPG

Official combined MPG for your petrol car

p/litre

UK average: ~153.5p/l. Adjust to your local price.

p/kWh

Check your energy bill — typically 24–32p/kWh on standard tariff

p/kWh

Typically 50–80p/kWh on rapid chargers

miles/kWh

Typical EVs: 2.5–4.5 mi/kWh. Default: 3.5

80% home / 20% public

Home charging is significantly cheaper — adjust this to reflect your situation

£

The extra upfront cost of buying an EV vs an equivalent petrol car. Set to 0 to skip break-even.

Results are estimates. Not financial advice.

Fill in your details

Enter your annual mileage, current car MPG, and charging assumptions. Click Calculate my true cost to see your personalised EV vs petrol comparison.

  • Cost per mile comparison
  • Annual and 5-year savings
  • Break-even point
  • 10-year cumulative cost chart

Reference prices

Avg.

Fuel

Petrol153.5p/l
Diesel168.6p/l

Electricity

Home26.1p/kWh
Public79p/kWh

UK national averages. Enter postcode for local prices. Why this matters →

EV vs diesel: the headline numbers

Diesel (55 MPG)

~£2,787/yr

20k miles

EV (80% home)

~£2,096/yr

~£691 saved

EV (50% home)

~£3,003/yr

~£216 more than diesel

EV (public only)

~£4,514/yr

~£1,727 more than diesel

Public rapid charging prices rose sharply through 2026 (now averaging 79p/kWh) while diesel also rose — but not enough to keep pace. Once public charging makes up half your miles or more, diesel now comes out ahead. Home charging is what makes the EV case work.

Based on 20,000 mi/yr. Diesel at 168.6p/litre. EV at 3.5 mi/kWh, 26.1p/kWh home, 79p/kWh public.

How to use this calculator for diesel

The calculator above compares an EV against a petrol car by default. To compare against diesel instead:

  • 1.Enter your diesel car's real-world MPG in the petrol car fields. Many modern diesel cars achieve 50–65 MPG on motorway runs.
  • 2.Adjust the fuel price to match current UK diesel prices (typically around 168.6p/litre in July 2026).
  • 3.Set your annual mileage — diesel tends to be more economical at high mileage, so use your realistic figure.

For a broader comparison covering petrol, diesel, and EV running costs in detail, see our main EV vs petrol running costs guide.

The diesel outlook in 2026

Diesel still makes sense for a shrinking set of drivers: very high mileage motorway users who cannot charge at home, and those who need a large estate or SUV where EV equivalents remain expensive. For most other use cases, the running cost advantage of an EV has become too large to ignore.

Company car drivers face a particularly stark choice. The 2% BIK rate for EVs compared to 25%+ for diesel company cars means thousands of pounds of tax difference per year — often dwarfing the fuel saving itself.

If you're considering an EV, check our best EV for high mileage guide and use the calculator above to run your own numbers.

Frequently asked questions

Is an electric car cheaper to run than a diesel in the UK in 2026?

Yes, if you charge mainly at home — and less clearly so otherwise, since public charging prices rose sharply through 2026. At 10,000 miles per year with 80% home charging at 26.1p/kWh and a diesel at 55 MPG and 168.6p/litre, the EV saves approximately £350–£650 per year in fuel costs depending on how the remaining 20% is charged. The gap is largest for high-mileage drivers and those on overnight EV tariffs.

How much does it cost to run an EV vs diesel per mile?

An EV at 3.5 miles/kWh charging entirely at home (26.1p/kWh) costs about 7.5p per mile. A diesel at 55 MPG and 168.6p/litre costs about 13.9p per mile. On an overnight EV tariff (7p/kWh), the EV drops to just 2p per mile.

Are diesels still worth buying for high mileage in 2026?

Diesel remains competitive for very high mileage drivers (20,000+ miles/year) who do mostly motorway driving and cannot charge at home. However, the combination of home charging and a high-mileage EV usually produces larger savings, especially when you factor in lower maintenance costs and the 2% BIK tax rate for company car drivers.

Is EV cheaper than diesel with public charging only?

No, not any more — this flipped in 2026. Public rapid charging averaged 79p/kWh across UK networks in mid-2026, up sharply from a couple of years ago. At 79p/kWh and 3.5 mi/kWh, an EV costs 22.6p/mile — noticeably more than a 55 MPG diesel at 13.9p/mile. Home charging is now essential for EVs to beat diesel on running costs; relying on public rapid charging alone no longer clears that bar.

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