Money & Budgeting

Electric vs Petrol Car Cost Calculator UK 2026 — True Running Costs

Calculate the real cost of electric vs petrol/diesel cars. Compare purchase price, fuel, tax, insurance, and find out which is cheaper for you.

By PocketWise · · 4 min read

Electric cars have higher purchase prices but lower running costs. Here’s how to calculate which is actually cheaper for you.

Quick Comparison: £30,000 Car Over 5 Years

Cost Petrol Electric
Purchase price £30,000 £35,000
Fuel/electricity (10k miles/yr) £8,750 £2,625
Road tax £950 £0*
Servicing £2,500 £1,250
Insurance £3,750 £4,500
ULEZ savings** £0 £6,250
5-Year Total £45,950 £43,625
Annual Cost £9,190 £8,725

*£0 until April 2025, then standard rates apply **If driving daily in ULEZ

Electric is £2,325 cheaper over 5 years despite costing £5,000 more to buy.

Fuel vs Electricity Costs

Cost Per Mile Comparison

Vehicle Type Efficiency Fuel Cost Cost Per Mile
Petrol (small) 45 mpg £1.40/L 14p
Petrol (medium) 35 mpg £1.40/L 18p
Petrol (SUV) 28 mpg £1.40/L 23p
Diesel (medium) 50 mpg £1.45/L 13p
Electric (home) 3.5 mi/kWh 12p/kWh 3.4p
Electric (public) 3.5 mi/kWh 65p/kWh 19p

Annual Fuel Costs by Mileage

Annual Miles Petrol (18p/mi) EV Home (3.5p/mi) Saving
5,000 £900 £175 £725
8,000 £1,440 £280 £1,160
10,000 £1,800 £350 £1,450
12,000 £2,160 £420 £1,740
15,000 £2,700 £525 £2,175
20,000 £3,600 £700 £2,900

Electricity Cost by Charging Method

Charging Type Cost Per kWh Cost Per Mile For 250 Miles
Home (standard rate) 12p 3.4p £8.50
Home (EV tariff) 7.5p 2.1p £5.25
Home (Octopus Go) 7.5p 2.1p £5.25
Workplace (free) £0 £0 £0
Public slow (7kW) 40p 11p £27.50
Public rapid (50kW+) 65p 19p £47.50

Road Tax (VED) Comparison

2026/27 Rates

Vehicle First Year Years 2+
Petrol (avg CO2 130g/km) £240 £190
Diesel (avg) £260 £190
EV (pre-Apr 2025 registered) £0 £0
EV (post-Apr 2025) £0 £190

5-Year Road Tax Cost

Vehicle 5-Year Cost
Petrol (from new) £1,000
EV (registered 2024) £0
EV (registered 2026) £760

EV road tax exemption ends April 2025 for new registrations.

Insurance Costs

Typical Insurance Comparison

Factor Petrol Electric
Average premium £550/year £680/year
Why higher for EV Repair costs, battery
Gap closing? Yes, rapidly

EV insurance is 15-25% higher on average, but the gap is narrowing.

Servicing and Maintenance

Annual Service Costs

Vehicle Annual Service Why
Petrol £400-600 Oil, filters, spark plugs
Diesel £450-650 Oil, filters, DPF
Electric £150-300 Brakes, tyres, coolant

Maintenance Differences

Item Petrol/Diesel Electric
Oil changes Every 10-12k miles None
Spark plugs Replace periodically None
Exhaust system Can fail None
Brake pads Regular replacement Last longer (regen braking)
Gearbox Can fail None (single speed)
Clutch Wears out None
Battery 12V standard Main battery warranty 8 years

5-Year Maintenance Estimate

Vehicle 5-Year Cost
Petrol £2,500
Diesel £2,800
Electric £1,250

Total Cost Calculator by Scenario

Scenario 1: 8,000 Miles/Year, Home Charging

5-Year Costs Petrol £25k EV £30k
Purchase (less trade-in) £15,000 £18,000
Fuel/electricity £7,200 £1,400
Road tax £950 £0
Insurance £2,750 £3,400
Servicing £2,500 £1,250
Total £28,400 £24,050
EV Saving £4,350

Scenario 2: 15,000 Miles/Year, Some Public Charging

5-Year Costs Petrol £30k EV £35k
Purchase (less trade-in) £18,000 £21,000
Fuel/electricity £13,500 £3,500
Road tax £950 £0
Insurance £2,750 £3,400
Servicing £2,500 £1,250
Total £37,700 £29,150
EV Saving £8,550

Scenario 3: 5,000 Miles/Year, City Driver (ULEZ)

5-Year Costs Petrol £20k EV £25k
Purchase (less trade-in) £12,000 £15,000
Fuel/electricity £4,500 £875
Road tax £950 £0
Insurance £2,750 £3,400
Servicing £2,500 £1,250
ULEZ charges (250 days/yr) £15,625 £0
Total £38,325 £20,525
EV Saving £17,800

When NOT to Go Electric

EV May Not Be Cheaper If:

Situation Why
No home charging Public charging expensive
Very low mileage Savings don’t offset price premium
Rural with no infrastructure Charging access issues
Tow heavy loads frequently Range impact
Keep cars 10+ years Battery degradation concerns

Break-Even Calculator

EV Premium Annual Mileage Needed to Break Even
£3,000 ~5,000 miles/year
£5,000 ~8,000 miles/year
£7,500 ~12,000 miles/year
£10,000 ~16,000 miles/year

Company Car/Salary Sacrifice

Benefit in Kind Rates 2026/27

Vehicle BiK Rate Tax on £40k Car (Higher Rate)
Petrol (avg) 28% £4,480/year
Diesel (avg) 32% £5,120/year
Electric 3% £480/year

EV company cars are 85-90% cheaper in benefit — massive saving for company car drivers.

Salary Sacrifice Example

£35,000 Electric Car Petrol Equivalent
Gross monthly: £450 N/A (no scheme)
Net cost (40% taxpayer): £300 Buy outright: £600/month
Includes: Insurance, maintenance, tax

Depreciation

3-Year Depreciation Comparison

Vehicle Type New Price 3-Year Value Depreciation
Petrol (avg) £30,000 £15,000 50%
Electric (avg) £35,000 £19,250 45%

EVs are holding value better than petrol — and improving.

Changes Coming

Factor Direction Impact on Case for EV
EV prices Falling Better
Electricity costs Stable/rising Slightly worse
Petrol prices Rising Better
Road tax on EVs Coming 2025 Slightly worse
Charging infrastructure Improving Better
Battery costs Falling Better

Key Takeaways

  1. EVs are cheaper to run — significantly lower fuel and maintenance
  2. Home charging essential — 3-4p/mile vs 15-20p/mile
  3. Higher mileage = bigger savings — fuel difference adds up
  4. Company cars: EV wins hugely — 3% vs 28%+ BiK
  5. Break-even typically 3-5 years — depending on mileage
  6. Consider total cost — not just purchase price

For related content, see our salary sacrifice calculator, car finance explained, and car affordability calculator.

Sources

  1. MoneyHelper — Everyday money