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EV Transition Calculator

Should you switch to an EV? Our independent calculator shows the real cost, including finance interest, road user charges and charging, not just the fuel you would save.
Updated 3 June 2026

Overview
  • Thinking of trading your petrol car for an electric one? Our calculator works out what the switch really costs once finance interest, road user charges and charging are counted, not just the fuel you would save.
  • Your charging cost depends on your power plan, so compare EV power plans and power companies alongside it.
  • Important: This is a guide only, not financial advice. Prices, rates and RUC all change, so confirm current figures before you commit. No saving is guaranteed.
EV Transition Calculator

Your current car

The EV you are considering

A cheaper home or night rate makes the biggest difference here. Compare EV power plans to see what you could pay overnight.

Finance

What the switch looks like

Monthly loan repayment
Amount to financeEV price, less trade-in and deposit
Total interest over the loan
Running cost now, on petrola year
Running cost as an EVa year, charging plus RUC
Running cost saving a year
The Bottom Line
Know This
Our View EVs make the most financial sense if you drive a lot, charge at home, and either buy used or keep the car for many years. The fuel savings are real, but since road user charges arrived they no longer cover a large finance bill quickly. The "save thousands" claims you see elsewhere almost always ignore the interest on the loan and the RUC you now pay. Run your own numbers above before a salesperson runs them for you.
Compare EV car finance Compare car insurance
Assumptions
  • Road user charges are $76 per 1,000km for a full EV, the same as a diesel, plus a $12.44 admin fee per licence (we assume 5,000km blocks bought online). Plug-in hybrids pay a lower $38 per 1,000km, which this tool does not model.
  • Charging cost blends your home and public split at the rates you set. The 30c/kWh home and 80c/kWh public defaults are starting points, not your rates - our comparison of power companies explains more.
  • The loan is a standard amortising loan at the rate and term you choose, with your trade-in and deposit reducing the amount borrowed. Check current rates on our car finance page.
  • Figures are estimates to help you compare, not a quote. They exclude insurance, servicing and depreciation, which differ by car.
  • Sources: NZTA Waka Kotahi (RUC) and MBIE (fuel and electricity prices).

How much is road user charges on an EV?

A full EV pays $76 per 1,000km, the same as a diesel, plus a $12.44 admin fee each time you buy a licence online. A plug-in hybrid pays a reduced $38 per 1,000km.

Does an EV cost more to insure?

Often, yes, because of higher purchase and repair costs, though it varies by model and insurer. This calculator does not include insurance, so we suggest you compare car insurance separately.

Should I buy a new or used EV?

EVs have depreciated heavily, which hurts if you buy new but helps if you buy used. A late-model used EV often gives most of the running-cost benefit at a far lower price, which shortens the payback the calculator shows.
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