EV Charging Cost Calculator Australia
Estimate energy drawn from the wall, session time and cost, then compare an annual home-and-public charging mix with a petrol vehicle. Every tariff, fee and efficiency assumption remains visible and editable.
Vehicle, charger and tariff
Charge-session dashboard
How the EV charging session is calculated
Battery energy added equals usable battery capacity multiplied by the percentage-point change from starting charge to target charge. A 60 kWh usable battery moving from 20% to 80% receives 36 kWh. Energy drawn from the wall is higher because charging is not perfectly efficient, so the calculator divides battery energy by the wall-to-battery efficiency. At 90% efficiency, delivering 36 kWh requires 40 kWh from the supply.
Session energy cost is wall energy multiplied by the home electricity tariff expressed in dollars per kilowatt-hour. The total then adds one connection fee and the time-based parking fee. Idealised time is wall energy divided by effective charger power. This is an energy calculation, not a promise about the vehicle’s displayed completion time.
Choose an effective charging power
Use the lowest effective limit across the electricity supply, charging equipment and vehicle for a first estimate. The Australian Government explains that a standard power point can provide up to about 2.4 kW, while dedicated home equipment may provide roughly 7 kW to 22 kW. The actual installation and vehicle can impose lower limits. A licensed electrician should assess dedicated charging equipment and the site’s capacity.
For DC fast charging, the peak number on a charger is rarely a constant session average. Charging commonly slows as the battery fills, and the vehicle may accept less than the charger can supply. If a real session added a known amount of energy over a known duration, calculate effective power as wall energy divided by hours and use that measured average for a closer replay.
Tariffs, solar and time of use
Electricity is generally priced per kWh, but the marginal cost of charging depends on the plan and time. Use the tariff that applies during the intended charging window. A flat-rate customer can enter the usage rate. A time-of-use customer should calculate separate off-peak and peak scenarios. Controlled-load eligibility, network rules and plan conditions vary, so confirm the bill and retailer information.
Rooftop solar is not automatically free fuel. Charging from solar may forgo a feed-in credit, and charging beyond live generation imports grid energy. A useful solar opportunity-cost input is the feed-in tariff for the solar portion and the import tariff for the grid portion, weighted outside this calculator. Include battery round-trip losses or household-battery wear only when those costs are relevant to the decision.
Annual EV energy model
Annual battery energy is yearly kilometres divided by 100 and multiplied by vehicle consumption in kWh per 100 km. Annual wall energy divides that figure by charging efficiency. The model then allocates wall energy between home and public charging using the entered percentage and prices each share at the corresponding cents-per-kWh tariff.
The annual output excludes connection, parking, idle and subscription charges because the number and structure of public sessions are unknown. Add expected annual fees separately before comparing ownership costs. It also excludes home-charger purchase and installation, vehicle finance, registration, insurance, servicing, tyres, depreciation and resale value. The result is an energy comparison, not total cost of ownership.
Petrol comparison boundaries
Petrol cost per 100 km is litres per 100 km multiplied by dollars per litre. Annual petrol cost scales that amount by yearly distance. Use a comparable vehicle and observed fuel consumption where possible. Official test values can help compare models, but driving conditions, load, speed, temperature, tyre pressure and auxiliary systems affect both electric and combustion vehicles.
The displayed saving is petrol fuel cost minus EV electricity cost. A negative result means the entered electricity mix costs more than the entered petrol fuel for the same distance. It does not prove one vehicle is cheaper overall. Purchase price and depreciation can outweigh energy differences, while maintenance, charging access and usage pattern can favour a different choice.
Inputs to collect before relying on the result
| Input | Good evidence | Common mistake |
|---|---|---|
| Usable battery | Vehicle documentation for usable capacity | Using gross pack capacity when a buffer is unavailable |
| Efficiency | Measured wall energy and battery energy over several sessions | Assuming every charger and season has the same loss |
| Home tariff | Current bill and charging time window | Using the daily supply charge as a per-kWh cost |
| Consumption | Long-term vehicle display or trip records | Selecting only a mild-weather urban trip |
| Public price | Current network app or charger display | Ignoring connection, parking, idle or membership fees |
| Petrol price | A representative local average | Choosing a temporary low or remote-area high without context |
Charging access and practical planning
Australian Government guidance notes that most EV charging occurs at home, but renters, apartment residents and drivers without off-street parking may depend more heavily on workplace or public infrastructure. Do not apply an 80% home share merely because it is the example. Base the mix on where the vehicle can reliably park, the kilometres driven between opportunities and any strata, landlord or electrical constraints.
Plan around charging availability as well as price. A cheaper charger that requires a special trip adds travel time and energy. Public networks can have different connector availability, power sharing, payment methods and idle rules. For regular routes, check live operator information and maintain a backup option. This calculator does not determine route range or charger compatibility.
Run a charging-cost sensitivity check
Save more than one result before choosing a plan or charger. A home case can use the normal overnight tariff and measured household charging share. A public-dependent case can lower the home share and enter the network rate most likely on regular routes. A winter or towing case can increase vehicle energy use. Keep distance constant while changing one assumption so the cost effect remains understandable.
For tariff comparisons, test the full charging window rather than the advertised cheapest period alone. If the vehicle cannot finish inside that window, price the remaining energy at the next applicable rate. Consider whether shifting household loads creates a new peak or changes a demand component on the plan. The calculator accepts one home tariff, so calculate a weighted rate from the kWh expected in each price period.
Record the bill date, plan name and charger price source beside a result. Rates and fee structures can change, and an old screenshot can otherwise look current. Recalculate after moving home, changing electricity plan, installing solar, changing commute, or observing a materially different long-term consumption figure.
Safety and installation limits
Do not infer wiring capacity from the cost result. Dedicated home charging equipment and any new circuit should be assessed and installed by appropriately licensed professionals under applicable rules. Avoid using damaged equipment or unsuitable extension arrangements. Follow the vehicle, cable and charging-equipment instructions, and obtain site-specific advice for strata buildings, rented premises or solar and battery integration.
The highest available power is not always necessary. Consider typical overnight parking time, daily energy need and existing electrical capacity. A lower-power solution may replenish routine travel within the available window, while occasional long trips can use public charging. Compare scenarios using daily required kWh rather than selecting equipment solely from the battery’s full capacity.
Frequently asked questions
Why is wall energy higher than energy added to the battery?
Charging has conversion and thermal losses. The calculator divides battery energy by the efficiency percentage so the supply energy and tariff cost reflect the entered loss assumption.
Does the calculator include a daily electricity supply charge?
No. A supply charge is normally paid for the premises regardless of one charging session. Include it only when comparing a plan or connection whose fixed cost changes because of the EV.
Can I use the charger label power to predict exact time?
Only as a rough scenario. The supply, charger and vehicle can impose lower limits, and battery management may reduce power during the session. Use an observed average for closer planning.
How do I model free workplace charging?
Set the relevant tariff to zero for an energy-only scenario, but keep any parking or access cost separate. Confirm that workplace access and pricing are dependable before treating them as an annual assumption.
Are public charging session fees in the annual result?
No. The annual model prices energy only because it does not know how many sessions occur. Add expected connection, idle, parking and membership charges for a fuller comparison.
Does this calculate EV range?
No. It estimates energy cost and idealised charging time. Range also depends on usable energy, conditions, route, speed, load and reserve choices, so follow vehicle guidance for trip planning.