Petrol vs Electric Car Running Cost Calculator
Compare the true cost of running petrol and electric vehicles in the UK. Get accurate calculations based on current fuel prices, electricity rates, and your driving habits.
Calculate Your Running Costs
Petrol Car
Per mile cost
Annual fuel cost
Electric Car
Per mile cost
Annual charging cost
Annual Savings with Electric
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| Comparison Factor | Petrol Car | Electric Car |
|---|---|---|
| Cost per mile | – | – |
| Weekly cost (200 miles) | – | – |
| Monthly cost (833 miles) | – | – |
| Annual fuel/charging cost | – | – |
How Running Costs Are Calculated
Petrol Car Calculations
For petrol vehicles, the cost per mile is determined by dividing the fuel price per litre by the car’s fuel efficiency in miles per gallon, then converting to the appropriate units. The formula accounts for the fact that one gallon equals 4.546 litres in the UK.
Electric Car Calculations
Electric vehicle costs depend on the car’s efficiency (measured in miles per kWh) and the electricity price. The calculation also factors in your charging habits, as public charging typically costs more than home charging.
Current UK Market Prices
As of September 2025, average petrol prices in the UK hover around £1.35 per litre, whilst home electricity rates average 27p per kWh. Public charging rates vary significantly, typically ranging from 40-80p per kWh depending on the charging network and speed.
Factors Affecting Running Costs
Vehicle Efficiency
Both petrol and electric vehicles vary considerably in their efficiency. Smaller, more aerodynamic cars typically achieve better efficiency ratings. For petrol cars, city driving often results in lower MPG compared to motorway driving, whilst electric cars are often more efficient in stop-start traffic due to regenerative braking.
Charging Location Impact
Where you charge your electric vehicle significantly affects costs. Home charging on standard tariffs costs approximately 27p per kWh, whilst overnight tariffs can reduce this to 7-10p per kWh. Public rapid charging can cost 40-80p per kWh, making it considerably more expensive for regular use.
Seasonal Variations
Cold weather affects both vehicle types but impacts electric cars more noticeably. Battery efficiency decreases in winter, potentially reducing range by 20-30%. Petrol cars may see slightly increased consumption in winter due to longer warm-up times and increased use of heating systems.
Beyond Fuel Costs: Total Cost of Ownership
Maintenance and Servicing
Electric vehicles typically require less maintenance than petrol cars. They have fewer moving parts, no oil changes, and brake pads last longer due to regenerative braking. Annual servicing costs for electric cars average £150-300 compared to £300-600 for petrol vehicles.
Taxation Changes
From April 2025, electric vehicles became subject to Vehicle Excise Duty (VED). New electric cars pay £10 in their first year, then £190 annually. Electric cars over £40,000 incur an additional luxury car supplement of £600 per year for five years. Company car tax remains highly favourable for electric vehicles at 2% benefit-in-kind rate.
Insurance Considerations
Electric vehicle insurance has historically been higher than petrol cars due to limited repair networks and expensive parts. However, this gap is narrowing as more insurers specialise in electric vehicles and repair infrastructure expands.
Making the Switch: What to Consider
Home Charging Setup
Installing a home charger costs £800-1,500 including government grants. Most electric car owners find home charging essential for maximising cost savings. If you cannot install home charging, relying on public charging networks significantly increases running costs.
Driving Patterns
Electric vehicles suit daily commutes and regular local journeys best. For frequent long-distance travel, consider charging infrastructure along your routes. Modern electric cars offer 250-400 miles of range, but rapid charging adds time to longer journeys.
Environmental Benefits
Beyond cost savings, electric vehicles produce zero direct emissions. With the UK’s increasingly renewable electricity grid, the carbon footprint of electric cars continues to decrease. Even accounting for manufacturing emissions, electric vehicles typically become carbon-neutral after 15,000-20,000 miles compared to petrol equivalents.
Frequently Asked Questions
How accurate are these calculations?
These calculations use current market averages and provide realistic estimates for typical driving conditions. Individual results may vary based on driving style, vehicle condition, and local price variations.
Do electric cars really save money?
For most UK drivers, electric cars offer significant fuel cost savings, typically 50-70% lower per mile. However, higher purchase prices mean total ownership costs depend on annual mileage, how long you keep the car, and available incentives.
What about rapid charging costs?
Rapid charging (50kW+) typically costs 40-80p per kWh, making it 2-3 times more expensive than home charging. For occasional use, this remains cheaper than petrol, but regular rapid charging reduces the cost advantage considerably.
How do company car taxes compare?
Electric company cars currently attract just 2% benefit-in-kind tax compared to 25-37% for petrol cars. For higher-rate taxpayers, this can save thousands of pounds annually, making electric company cars highly attractive despite higher list prices.
Will electricity prices rise?
Electricity prices fluctuate based on wholesale energy markets and government policy. However, the efficiency advantage of electric motors over internal combustion engines means electric cars are likely to remain cheaper per mile even with price increases.