Electric vs petrol: calculate the cost of 100 km before you buy
Use a transparent example to compare electric charging and petrol costs per 100 km, then add insurance, maintenance and depreciation to your budget.
The calculation you can reuse
Electricity cost per 100 km = electricity drawn from the charger in kWh per 100 km × price per kWh. Petrol cost per 100 km = litres per 100 km × price per litre. Using charger energy includes charging losses; an in-car consumption display may not. Use matching currencies and comparable driving conditions.
An illustrative example, not current tariffs
Assume 18 kWh drawn per 100 km and an electricity price of €0.25/kWh. That is €4.50/100 km. Assume the petrol alternative uses 6 litres at €1.80/litre: €10.80/100 km. The difference is €6.30 per 100 km, or €945 across 15,000 km. These are invented inputs for the calculation, not measured vehicle results or local price quotes.
Public charging can change the result
With the same 18 kWh but a price of €0.65/kWh, the electric result becomes €11.70/100 km. For mixed charging, weight prices by energy purchased at each tariff. Include session, parking or subscription fees separately. Repeat the calculation with your electricity bill, local fuel price and realistic consumption.
What belongs in the full budget?
Add purchase price, financing charges, insurance, maintenance, tyres, taxes and any charger installation, then subtract the expected resale value. Keep resale as an assumption rather than a guaranteed return. Compare two HaveKar listings with the same intended ownership period and annual distance. The linked DOE calculator offers another framework; replace its assumptions with values relevant to your market.
Sources
Sources checked: September 10, 2026
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