This interactive calculator compares the running cost of an electric vehicle against a petrol car, using the latest New Zealand fuel prices published weekly by MBIE. Enter your driving distance and see how much you would save each week, each year, and over five years. All calculations update instantly as you adjust the inputs.
Your car and your EV choice
Your driving
Cumulative savings over 10 years
How This Calculator Works
The calculator takes the national average pump price for regular petrol, published weekly by MBIE, and compares what you would spend on fuel against what you would spend charging an equivalent electric vehicle at home. The three numbers you can adjust are: how far you drive per week, how efficient your current petrol car is, and how efficient the EV you are comparing against would be. The home electricity rate is also adjustable since power prices vary by retailer and plan.
The calculations are deliberately straightforward. Weekly petrol cost equals your weekly kilometres multiplied by your car’s fuel efficiency (in litres per 100 km) multiplied by the current pump price. Weekly EV cost equals your weekly kilometres multiplied by the EV’s energy efficiency (in kilowatt hours per 100 km) multiplied by your electricity rate. The saving is the difference, extrapolated out to weekly, monthly, yearly, and five-year totals.
Picking Your Cars
Selecting your actual petrol car from the dropdown makes the calculator far more accurate. The efficiency figures used are based on real-world fuel consumption in New Zealand driving conditions, which is typically 10 to 20 percent higher than the manufacturer combined cycle figures quoted at the time of sale. Hybrid models are listed separately because their real-world efficiency is substantially better than a non-hybrid version of the same car. A Toyota Corolla Hybrid uses about 4.8 litres per 100 km; a Toyota Corolla petrol uses about 7.5 litres per 100 km.
For the EV side, the dropdown includes the most common EVs on sale in New Zealand. Small cars like the BYD Dolphin, Nissan Leaf, and Peugeot e-208 use around 14 to 16 kilowatt hours per 100 km. Mid-sized cars like the Tesla Model 3 and BYD Atto 3 use 15 to 17. Larger SUVs and electric utes use 18 to 25. The figures used are based on real-world efficiency including heating, air conditioning, and motorway speeds. If you already own an EV and know your exact figure, use the advanced options to enter it directly.
What Is Not Included in the Savings
This calculator only looks at fuel costs versus charging costs. In practice, switching to an EV typically delivers additional savings that the calculator does not quantify. Maintenance costs are significantly lower for EVs because there are far fewer moving parts. No oil changes, no spark plugs, no exhaust system to replace, no timing belts, no clutch. Brake pads last longer because EVs use regenerative braking. Fluids are largely limited to coolant and washer fluid.
The EECA estimates that maintenance on an EV costs approximately a third of what a petrol car costs to maintain over the same distance. Registration is also slightly lower for electric vehicles. Depreciation patterns have historically favoured petrol cars, but that gap has narrowed significantly as the EV market has matured and battery longevity has proven itself in real-world fleets. For a fuller picture, the EECA running cost calculator includes these additional factors.
What Assumptions Affect the Result
The single biggest variable is the electricity price you use for charging. At home on an off-peak or night rate, rates can be as low as 15 to 20 cents per kilowatt hour. At standard residential rates, 25 to 32 cents is typical. At public fast chargers, prices range from 60 to 90 cents per kilowatt hour, which significantly reduces the cost advantage over petrol. The calculator defaults to 28 cents per kilowatt hour, which reflects typical day-rate home charging across New Zealand retailers. If you plan to charge mostly at home on a cheaper night rate, adjust the slider down and watch the savings grow.
The petrol car efficiency figure matters nearly as much. A fuel-efficient small car like a Toyota Yaris or Suzuki Swift uses around 5 to 6 litres per 100 km, while a large SUV or ute can use 11 to 13 litres. The default of 8 litres per 100 km reflects a typical medium-sized sedan or wagon. The more fuel-thirsty your current vehicle, the bigger the saving from switching to an EV.
The EV efficiency figure depends on the model. A Tesla Model 3 or Hyundai Kona Electric typically uses around 14 to 16 kilowatt hours per 100 km. A Nissan Leaf uses 15 to 17. Larger electric SUVs like the BYD Atto 3 use 18 to 20. Electric utes use 22 to 26. The calculator defaults to 16 kilowatt hours per 100 km, which reflects a typical small-to-mid-size EV.
Why Fuel Prices Matter More Than Ever
The calculator updates every time MBIE publishes new weekly fuel price data. During the 2026 Strait of Hormuz crisis, pump prices have doubled for some fuels, making the EV running cost advantage substantially larger than it was a year ago. For a household driving 250 kilometres a week in an average petrol car, the weekly fuel bill has risen from around $60 a year ago to over $70 now. A switch to an EV charging at home turns that into roughly $11 a week, a saving of over $3,000 a year at current prices.
For the current week’s pump price in context, see our New Zealand Fuel Prices weekly tracker. For the live electricity generation mix and wholesale prices that determine what retailers charge, see our New Zealand Electricity Dashboard.
Is an EV Right for You?
The savings numbers above reflect running costs only. The decision to switch also depends on how you drive, where you park, and how long you keep your cars. EVs work best for households that do most of their driving on predictable routes and can charge at home overnight. They work less well for people with no off-street parking who would need to rely on public chargers at higher rates, or for people doing regular long-distance trips where charging stops add time to every journey.
EV purchase prices have fallen significantly over the past three years, and the range of used EVs on the New Zealand market has grown substantially. A Nissan Leaf imported from Japan can now be bought for under $15,000. New EVs from Chinese manufacturers like BYD and MG have entered the market at price points competitive with mid-range petrol equivalents. For most people making a new car purchase today, the question is no longer whether an EV makes financial sense but when.
About the Data
Pump prices used in this calculator come from MBIE’s Weekly Fuel Price Monitoring dataset and are updated automatically when new data is published. The electricity rate default reflects typical New Zealand residential day rates compiled from several retailers and is conservative. The calculator does not track real-time wholesale electricity prices since retail consumers do not pay wholesale rates directly, though these wholesale prices are tracked separately on our electricity dashboard.