EV vs Petrol Running Cost Calculator

This calculator works out whether an electric vehicle or a petrol car is cheaper to run for your own driving in New Zealand, rather than relying on general claims about EV savings. You enter your annual distance, then figures for each vehicle: for the EV, its efficiency in kWh per 100km, your electricity price, the road user charges you pay per 1000km, and annual servicing; for the petrol car, its fuel use in litres per 100km, the petrol price, and annual servicing. Road user charges are included because EVs now pay these directly, while petrol cars cover the equivalent through fuel excise tax, so leaving RUC out would skew the comparison. As you type, the calculator shows the annual running cost for each vehicle, the saving between them, and a plain verdict on which is cheaper to run at your numbers. A worked example shows a typical 12,000km-a-year driver comparing a 17kWh per 100km EV against an 8L per 100km petrol car. Use it with your actual driving distance and current local power and petrol prices, updating the figures whenever prices move, since the outcome is sensitive to both. This tool covers running costs only; it does not include purchase price, depreciation, finance costs or battery replacement, all of which matter for a full ownership comparison. Treat the results as an indicative running-cost estimate rather than financial advice.

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Electric vehicle

Petrol car

Road user charges apply to electric vehicles and are included here; petrol cars pay tax through fuel instead. This compares running cost only, not purchase price, depreciation or battery replacement. Prices change, so use current figures. Estimate only, not financial advice.