EV vs Petrol Cost Calculator
Compare EV and petrol running cost per 100 km, per trip or per year, and see the saving per kilometre and per month at every electricity price tier.
EV vs petrol cost
Hybrid $9.00
Typical EV vs petrol cost in New Zealand
For the same distance, EVs often cost less to run than petrol vehicles because electric drivetrains use energy more efficiently. The gap can widen further when charging at home on a lower electricity tariff.
| Vehicle type | Fuel cost per 100 km | Annual fuel cost (14,000 km) |
|---|---|---|
| EV at EV off peak ($0.12/kWh) | $1.92 | $269 |
| EV at off peak ($0.25/kWh) | $4.00 | $560 |
| EV at Home standard rate ($0.39/kWh) | $6.24 | $874 |
| Petrol vehicle (8.0 L/100 km at $3.00/L) | $24.00 | $3,360 |
EV figures based on a typical EV (16 kWh per 100 km). Petrol figures based on a medium car using 8.0 litres per 100 km at $3.00 per litre. The calculator above lets you replace both sides of this comparison with your own figures.
How this calculator works
This calculator compares the running cost of an electric vehicle with a petrol vehicle over the same distance. It shows the saving at every common electricity price tier so you can see how the comparison changes depending on where and how you charge.
EV formula
EV cost = Distance (km) ÷ 100 × EV efficiency (kWh per 100 km) × Electricity price ($ per kWh)
Petrol formula
Petrol cost = Distance (km) ÷ 100 × Fuel use (L per 100 km) × Petrol price ($ per litre)
Worked example
Distance: 100 km
EV efficiency: 16 kWh per 100 km
Electricity price: $0.39 per kWh (Home standard rate)
Fuel use: 8 L per 100 km
Petrol price: $3.00 per litre
EV: 100 ÷ 100 × 16 × $0.39 = $6.24
Petrol: 100 ÷ 100 × 8 × $3.00 = $24.00
Saving: $24.00 − $6.24 = $17.76
Price preset guide
Home solar is charging from your own rooftop generation. The cost shown is not a bill — it is the feed-in credit you give up by using that energy yourself instead of exporting it, which is what makes solar charging the cheapest option here.
EV off peak refers to very low EV specific overnight pricing offered by some electricity retailers.
Home off peak refers to a more typical off peak residential rate.
Home standard rate refers to a flat residential electricity tariff.
Public AC, DC fast and Ultra rapid DC refer to common public charging categories. Prices vary between networks and locations.
These labels are shorthand for the tiers used across this site. Set your own rate for any of them in the My EV panel and every figure here recalculates. Which tier you actually use decides how large the petrol saving is, so compare against the row that matches your own charging.
Where a hybrid sits between the two
For a lot of buyers the real choice is not electric versus petrol at all — it is electric versus a hybrid, because a hybrid removes the charging question entirely. The comparison above includes a hybrid column for that reason.
A conventional hybrid uses a small battery and an electric motor to recover energy that a petrol car wastes, mostly through braking and idling. It never plugs in. Typical real-world consumption for a mid-size hybrid sits somewhere around 4 to 5 litres per 100 km against roughly 7 to 9 for the equivalent petrol car, so it removes something like 40 to 45 percent of the fuel bill. That is a genuine saving, and it arrives without a charger, without a tariff decision and without thinking about range.
What it does not do is close the gap to an EV charged at home. Halving a fuel bill still leaves you paying for fuel; an EV on a cheap overnight tariff is paying a small fraction of it. Run the numbers above and the ordering usually comes out the same way: EV charged at home, then hybrid, then petrol — with EV charged exclusively on ultra-rapid public DC sometimes landing near or above the hybrid, which is the one case where the hybrid genuinely wins on running cost.
That last point is the useful one. If you have off-street parking and can charge overnight, the EV column is the cheapest by a wide margin. If you cannot charge at home and would depend on public fast charging, a hybrid becomes a much more serious contender than the headline "EVs are cheaper to run" suggests. Where you can plug in matters more than which powertrain you pick.
A note on plug-in hybrids
A plug-in hybrid (PHEV) is a different vehicle from the conventional hybrid modelled here. It has a larger battery and does plug in, giving perhaps 40 to 80 km of electric range before the petrol engine takes over. Its running cost therefore depends almost entirely on how disciplined you are about charging it: charged daily and used for short trips it behaves close to an EV, and left uncharged it behaves like a slightly heavy petrol car. Because the answer swings so wildly on driver behaviour, a single figure would be misleading, so this calculator does not model one. To approximate it, run the EV column for the share of your driving inside the electric range and the petrol column for the rest.
Road user charges differ too. A plug-in hybrid pays RUC at a reduced rate, because it also buys petrol and therefore pays fuel excise on part of its driving, where a full electric vehicle pays the standard light EV rate. The road user charges calculator covers both.
What this comparison includes, and what it leaves out
This calculator compares fuel and energy cost only. It answers one question precisely: for the same distance, what does the electricity cost versus what the petrol costs. That is the largest single running-cost difference between an EV and a petrol car, and it is the one you can calculate accurately from figures you already know.
It deliberately does not fold in servicing, tyres, insurance, registration or depreciation. Those vary far more by individual circumstance than fuel does — two drivers with the same car can pay very different insurance premiums — and burying them in a single headline number would make the result look more precise than it really is.
The direction those costs push is worth knowing. Servicing is generally cheaper on an EV, because there is no oil, no spark plugs, no timing belt and far less brake wear thanks to regenerative braking. Tyres can run the other way: EVs are heavier and deliver torque instantly, which can wear tyres faster. Insurance and depreciation depend on the specific model. If you want those included, the EV running cost calculator adds servicing to the picture, and the EV vs petrol total cost comparison guide walks through the full ownership picture.
On road user charges
Petrol prices include fuel excise duty, which is how petrol vehicles pay for road use. Electric vehicles buy no petrol, so since 1 April 2024 they have paid road user charges directly instead, at $76 per 1,000 km for a light EV. Plug-in hybrids pay a reduced rate, because they buy some petrol and therefore some excise as well.
This matters more than it looks. RUC works out at roughly 7.6 cents per kilometre and is charged on distance rather than energy, so it lands on your running cost no matter how cheaply you charge. A comparison that leaves it out is not comparing like with like, because the petrol figure already has its road funding inside the pump price. The road user charges calculator works through what it costs at your own distance.
Getting an honest comparison
The result is only as good as the two numbers you feed it, and the petrol side is where most comparisons go wrong.
Use your car's real fuel consumption, not the manufacturer's combined figure. Official consumption numbers come from standardised lab cycles, and real-world driving is routinely ten to twenty percent worse, sometimes more for short urban trips where the engine spends much of its time cold. If you have been tracking litres against kilometres at the pump, that number is far more trustworthy than the brochure. The same caution applies in reverse to EV efficiency: the figure on the spec sheet is a best case, and your own consumption display is closer to the truth.
The other number that matters more than people expect is the electricity price. The calculator shows every tier at once for exactly this reason. An EV charged overnight on a dedicated EV tariff and the same EV charged exclusively on ultra-rapid DC are not remotely the same running cost — the gap between the cheapest and dearest row in the comparison is usually larger than the difference between many EVs and many petrol cars. Where you charge matters more than what you drive.
If you have set your car using the My EV button, the efficiency above is already your vehicle's. If you have also set your own electricity rate, every figure on this page is using it.
Frequently asked questions
Is an EV or a hybrid cheaper to run?
An EV charged at home is almost always cheaper, usually by a wide margin, because electricity on an overnight tariff costs a fraction of petrol per kilometre and a hybrid still buys fuel for every kilometre it drives. The exception is the driver who cannot charge at home and relies on ultra-rapid public DC charging, where the EV column can land close to or above the hybrid. If you have off-street parking the EV wins comfortably; if you do not, run both columns above with your own figures before deciding.
What fuel consumption should I use for the hybrid column?
The default of 4.5 litres per 100 km reflects a typical mid-size conventional hybrid in real-world use. Small hybrids can better it and larger hybrid SUVs will use more, so substitute the figure for the specific model you are considering. As with the petrol column, prefer a real measured number over the manufacturer's combined-cycle figure, which is generally optimistic. Leaving the field empty removes the hybrid from the comparison entirely.
Does this include servicing, insurance and depreciation?
No. This calculator compares fuel and energy cost only, because that is the difference you can calculate precisely from figures you already have. Servicing generally favours the EV, since there is no oil, no spark plugs and far less brake wear. Tyres can favour the petrol car, because EVs are heavier and wear tyres faster. Insurance and depreciation depend heavily on the specific model. For a fuller picture, use the EV running cost calculator, which includes servicing, or read the EV vs petrol total cost comparison guide.
What fuel consumption figure should I use for my petrol car?
Use your own measured consumption if you have it: divide the litres you put in by the kilometres travelled, then multiply by 100. Manufacturer combined-cycle figures come from standardised lab tests and real-world driving is commonly ten to twenty percent worse, particularly on short urban trips. Using the brochure figure will understate what your petrol car actually costs you and make the EV saving look smaller than it is.
Why does the saving change so much between electricity price tiers?
Because electricity price is the single biggest variable in EV running cost. Charging overnight on a dedicated EV tariff can cost roughly a tenth of what ultra-rapid DC charging costs per kilowatt-hour. Petrol prices move within a much narrower band. That is why the comparison shows every tier at once rather than a single number: where you charge changes the answer more than which EV you drive.
Do EVs pay a road user charge in New Zealand?
Yes. Light electric vehicles have paid road user charges since 1 April 2024, at $76 per 1,000 km, which is about 7.6 cents per kilometre. Petrol vehicles pay for road use through fuel excise duty built into the pump price instead, so both contribute; the difference is the mechanism. RUC is charged on distance rather than energy, so it does not fall when you charge more cheaply, and any EV versus petrol comparison that omits it overstates the saving.
What if I charge from my own rooftop solar?
Then your marginal cost is closer to what you would have been paid for exporting that energy to the grid, rather than what you pay to import it. Feed-in tariffs are typically well below retail rates, so solar charging usually sits at or below the cheapest tier shown here. You can enter your own figure in the electricity price field to model it. The catch is timing: solar charging only works if the car is home and plugged in during daylight, which suits some driving patterns and not others.
Is comparing against my current car fair if it is much older?
It is fair if the question you are asking is "what would switching save me", because your current car is the real alternative. It is less useful if you are choosing between a new EV and a new petrol car, since a modern petrol equivalent will likely use less fuel than an older one. Decide which question you are answering, then use the fuel consumption figure that matches it.
