Personal Finance
Electric vs Petrol Car Cost Calculator
Enter annual distance, petrol economy and price, EV consumption and electricity price, plus optional other costs.
Electric or petrol — which costs less to run?
Running-cost comparisons between petrol and electric cars are dominated by annual distance, petrol economy (MPG or L/100 km) and fuel price versus EV consumption in kWh/100 km and electricity price. Convert everything to a yearly energy bill, then optionally add other annual costs (servicing stereotypes, road tax differences, tyres) in the separate fields. The tool reports each energy cost, totals with “other”, and the difference. It is not a full total cost of ownership — depreciation, insurance quotes and financing dwarf energy for many drivers. For time spent travelling see the lifetime commute calculator when location choices matter as much as fuel.
Worked example
10,000 km/year, 7 L/100 km at £1.45/L ≈ £1,015 petrol energy. EV at 16 kWh/100 km and £0.28/kWh ≈ £448 energy — before “other” costs.
Limits and assumptions
UK gallons used for MPG mode. Home vs public charging rates differ — enter a blended electricity price. Battery degradation and petrol short trips are not modelled.
Frequently asked questions
What do MPG, EV and kWh mean?
MPG is miles per gallon (how far the petrol car goes per gallon). EV means electric vehicle. kWh is kilowatt-hour — the usual unit on an electricity bill and for battery use.
MPG or L/100 km?
Use whichever matches your handbook or onboard computer; toggle the mode so the maths matches. L/100 km is litres of fuel per 100 kilometres (lower is better).
Should I use peak electricity price?
Use a realistic average including home off-peak and any public DC rapid share.
Why might petrol still win on paper?
Very low annual mileage, expensive electricity, or large “other” EV costs can flip the totals — read both columns.