Why use this calculator
Electric cars usually cost more to buy and less to run, so the only honest question is how long the running savings take to repay the higher price, and whether you will still own the car by then. The answer swings hard on details that headline comparisons skip: how much of your charging happens at home on a cheap overnight or solar rate versus at public fast chargers that can cost twice as much, how far you drive, and what petrol costs where you live.
This calculator blends your home and public charging into one price, converts both cars to a cost per 100 km so they can be compared directly, adds the servicing difference, and then shows the break-even point and the running total year by year. There is also a field to test a road user charge, because EV drivers do not pay the fuel excise that petrol drivers pay at the pump and governments have been discussing a replacement.
How to use it
- Enter the kilometres you drive a year from your odometer or service records.
- Petrol car fuel use comes from the trip computer or the Green Vehicle Guide, and the petrol price from recent receipts.
- EV energy use is on the Green Vehicle Guide or the car's display.
- Home electricity price is the usage rate on your power bill.
- Estimate the share of charging you will do at public chargers, and enter the price per kWh shown in the charging network's app.
- Leave the road user charge at zero unless you are testing one.
- Enter both drive away prices from dealer quotes, both servicing costs from the manufacturers' schedules, and how long you will keep the car.
What each result means
- Yearly running saving with the EV
- How much less the EV costs to run each year in energy and servicing. Negative means the petrol car is cheaper to run.
- Break-even point
- How many years of running savings it takes to repay the EV's higher purchase price, before resale values.
- Yearly km to break even in your ownership period
- How many kilometres a year you would need to drive for the EV's running savings to repay its higher price within the years you plan to keep it. Drive more than this and the EV comes out ahead.
- EV price that breaks even in your ownership period
- The highest EV price at which running savings over your ownership period exactly make up the difference to the petrol car. Use it as a negotiating ceiling, remembering resale values are not included.
- Petrol cost per 100 km
- Fuel cost to drive 100 km in the petrol car at the consumption and pump price you entered.
- EV energy cost per 100 km
- Electricity cost to drive 100 km in the EV at your blended charging price, plus any road user charge entered.
- Blended electricity price
- Your average price per kWh across home and public charging, weighted by the share you do at each.
- Petrol spend per year
- What the petrol car costs in fuel over a year at your kilometres, consumption and pump price.
- EV energy and road charge per year
- What the EV costs in electricity over a year, plus any road user charge you chose to test.
- Servicing saving per year
- The difference in yearly servicing cost. Electric cars have no oil, spark plugs or exhaust to maintain.
- EV purchase premium
- How much more the EV costs to buy than the petrol car. Negative means the EV is cheaper up front.
- Petrol car: total over ownership period
- Purchase price plus fuel and servicing over the years you plan to keep the petrol car.
- EV: total over ownership period
- Purchase price plus electricity, road charge and servicing over the years you plan to keep the EV.
- EV advantage over ownership period
- The petrol total minus the EV total. Positive means the EV is the cheaper car overall across your ownership period.
The formula
Petrol cost per 100 km equals litres per 100 km times the price per litre. The blended electricity price equals the home price times the home share plus the public price times the public share. EV cost per 100 km equals kWh per 100 km times the blended price, plus the road user charge in cents per km. Yearly energy cost equals kilometres divided by 100 times the cost per 100 km. Yearly saving equals petrol energy plus petrol servicing, minus EV energy plus EV servicing. Break-even years equal the price premium divided by the yearly saving.
How this number is used in practice
Where you charge matters more than which EV you buy. Charging at home at 30 cents a kWh, a typical EV costs around five dollars per 100 km, and on a solar or overnight EV tariff it can be half that. Rely on public fast chargers at 60 cents or more and the cost doubles, which erases much of the gap with an efficient petrol car. Renters and apartment dwellers without a charger should set the public share high to see their real number.
For salary earners the biggest EV saving is often not running cost at all. Eligible zero or low emission cars first held and used after 1 July 2022, priced under the luxury car tax threshold for fuel efficient vehicles, are exempt from fringe benefits tax when provided through an employer or a novated lease, so the lease is paid from pre tax salary without the usual FBT cost.
Plug in hybrids lost that exemption from 1 April 2025 except under existing arrangements. On road user charges, Victoria's per kilometre EV charge was struck down by the High Court in 2023, and petrol drivers pay fuel excise that EV drivers avoid, so a national replacement remains possible.
Worked examples
15,000 km a year, $35,000 petrol car at 8 L/100km and $2.00, $50,000 EV, 20 per cent public charging
The EV costs $6.12 per 100 km against $16.00 for petrol, saving about $1,832 a year, so it breaks even in 8.2 years.
25,000 km a year, home charging only on an 8 cent overnight tariff
The EV costs $1.36 per 100 km, saving about $4,010 a year, so the $15,000 premium is repaid in 3.7 years.
8,000 km a year, all public fast charging at 65 cents, a 2.5 cent per km road charge
The EV costs $13.55 per 100 km, saving only about $546 a year, so the $15,000 premium takes 27.5 years to repay.
When people use it
- Deciding whether an EV pays for itself within the years you will keep it
- Testing how much home solar or an overnight tariff improves the numbers
- Checking the cost for renters who rely mostly on public charging
- Stress testing the savings against a possible future road user charge
- Comparing a specific EV with the petrol version of a similar model
Tips
- Ask your retailer about an EV or time of use tariff. Overnight rates can be a fraction of the standard usage rate.
- Charging from rooftop solar in the middle of the day costs you only the feed in tariff you give up, often a few cents a kWh.
- If you salary package, compare a novated lease on an eligible EV. The fringe benefits tax exemption can be worth more than the running savings.
- Check your state for EV stamp duty concessions or registration discounts, and enter the price after them.
- Use real world consumption, not the label. Highway driving and heating or cooling raise EV energy use more than city driving.
- Insurance on EVs is often higher than on comparable petrol cars, so get quotes for both before deciding.
What it assumes, and where it stops being accurate
- Energy prices, servicing and kilometres are held flat in today's dollars across the ownership period.
- Resale values, battery replacement, insurance and registration differences are not included.
- No road user charge applies unless you enter one. Petrol prices already include fuel excise.
- Home charging losses of around 10 per cent are not added, so enter a slightly higher kWh figure for a tighter estimate.
- Fringe benefits tax savings on a novated lease are not modelled and depend on your salary and the lease terms.
Terms used on this page
- kWh per 100 km
- The electricity an EV uses to travel 100 kilometres, the electric equivalent of litres per 100 km.
- Break-even point
- The number of years of running savings needed to repay a higher purchase price.
- Novated lease
- A car lease paid by your employer from your salary, which can be free of fringe benefits tax for eligible EVs.
- Road user charge
- A per kilometre charge on vehicles that do not pay fuel excise, proposed as a way to fund roads.
Questions people ask
- Is an EV cheaper to run than a petrol car in Australia?
- Almost always per kilometre. At 17 kWh per 100 km and 30 cents a kWh, an EV costs about $5.10 to drive 100 km, against $16 for a petrol car using 8 litres at $2.00. The gap narrows with public fast charging, and the higher purchase price means the savings take years to recover.
- How long does an EV take to pay for itself?
- It depends on the price premium, how far you drive and where you charge. A driver covering 15,000 km with mostly home charging typically saves $1,500 to $2,500 a year, so a $15,000 premium takes roughly six to ten years. High mileage drivers with cheap home charging break even much sooner.
- What is the FBT exemption for electric cars?
- Battery electric and hydrogen fuel cell cars priced below the luxury car tax threshold for fuel efficient vehicles, first held and used from 1 July 2022, are exempt from fringe benefits tax when provided by an employer, including through a novated lease. Plug in hybrids lost the exemption from 1 April 2025 except under existing commitments.
- Do EV drivers pay a road user charge?
- Not at present. Victoria introduced a per kilometre charge, but the High Court struck it down in 2023 because states cannot impose that kind of tax. Petrol drivers fund roads partly through fuel excise, which EV drivers do not pay, so a national road user charge has been discussed. Use the field to test one.
- How much does public fast charging cost?
- Public DC fast chargers in Australia commonly charge around 50 to 80 cents a kWh, and some add idle fees. That can be double or triple a home tariff, which is why drivers who rely on public charging see much smaller savings. Slower public AC chargers and some council chargers can be cheaper or free.
Use this with
EV vs Petrol Cost Calculator answers one part of the question. These pick up where it stops: Car Running Cost Calculator, Fuel Cost Calculator, Solar Panel Savings Calculator, Car Loan vs Lease Calculator and Fuel Efficiency Calculator.
Where these figures come from
Figures and rules on this page follow Australian law and ATO guidance.
- Green Vehicle Guide. Official energy and fuel consumption figures for new vehicles in Australia
- Energy Made Easy. Government comparison of electricity plans and time of use tariffs
- Australian Taxation Office. Fringe benefits tax electric car exemption
EV vs Petrol Cost Calculator produces an estimate for general information. It is not financial, tax, medical, legal or engineering advice. read the full disclaimer. Spotted a wrong number? Report it and it gets fixed. The form picks up this calculator and the inputs you used.