The short answer#
Charging an EV costs the energy it needs, multiplied by the price per kilowatt-hour at the time and place you charge. Home charging is usually the cheapest, and public DC fast charging is the most expensive.
For most Australian drivers, a home-charged EV costs a few cents per kilometre — well below petrol or diesel. The exact number depends on the tariff, the car's efficiency and the schedule.
The basic formula#
Charging cost = energy needed ÷ charging efficiency × price per kWh.
Three factors:
- The energy the car needs — a typical EV uses 15–20 kWh per 100 km.
- Charging losses — roughly 10% is lost as heat and in conversion, so you draw more from the wall than the battery stores.
- The price per kWh — the tariff at the time and place of charging.
A car that needs 18 kWh per 100 km, with 10% losses, draws about 20 kWh from the wall. At 30c/kWh, that is $6.00 per 100 km, or 6 cents per kilometre.
Home charging#
Home charging is the default for daily driving, and it is the cheapest option.
- Flat tariff — the simplest comparison, often 25–40c/kWh.
- Time-of-use — off-peak overnight rates can be much lower.
- Solar — charging from surplus solar is the cheapest of all, though it depends on the sun and the car being home.
The off-peak EV charging guide shows how scheduling cuts the cost.
Public charging#
Public charging costs more per kilowatt-hour, and the price varies by network and location.
- AC destination chargers — slower, cheaper, often at shopping centres and workplaces.
- DC fast chargers — faster, more expensive, on highways and main routes.
Public charging is for trips, top-ups and the times you cannot charge at home. Relying on it for daily use is expensive.
A worked comparison#
Take a car driving 20,000 km a year, at 18 kWh per 100 km — about 3,600 kWh of battery energy, or roughly 4,000 kWh from the wall with losses.
| Charging method | Rate | Annual cost | Per kilometre |
|---|---|---|---|
| Home, off-peak | 12c/kWh | ~$480 | ~2.4c |
| Home, flat | 30c/kWh | ~$1,200 | ~6.0c |
| Home, solar | Avoided cost | ~$0–$400 | ~0–2.0c |
| Public DC | 60c/kWh | ~$2,400 | ~12.0c |
These are illustrative. The point is the spread: the rate you charge at moves the annual cost by a lot.
What changes the number#
- the tariff — the biggest single factor
- the schedule — off-peak vs peak makes a real difference
- charging losses — about 10%, unavoidable
- the car's efficiency — heavier, faster cars use more per kilometre
- climate — cold weather reduces battery efficiency
- public charging share — the more you rely on it, the higher the cost
Home vs public charging#
For most drivers, home charging covers daily use and public charging covers the rest. The car is home most of the time, and home charging is cheaper. Public charging is for the trips that cannot be covered at home.
Our EV charging tariffs guide compares the tariff side in detail, and the home vs public section there shows the worked comparison.
Bottom line#
An EV's running cost is the energy it needs times the rate you pay, and home charging is usually the cheapest by a wide margin. Schedule it off-peak or from solar, add the charging losses, and the per-kilometre cost is a few cents. The rate and the schedule matter more than anything else.
For the tariff comparison, see EV charging tariffs.
Straight answers
Questions people ask about this
How much does it cost to charge an EV at home?
It depends on the tariff and the car. A typical home charge from a 30c/kWh flat rate might cost around $4.50 to $6.00 for 100 km of driving; on a 12c/kWh off-peak rate it could be under $2.00. Add roughly 10% for charging losses.
Is it cheaper to charge an EV at home or public?
Home charging is usually cheaper, especially off-peak or from solar. Public AC charging costs more, and public DC fast charging is the most expensive per kilowatt-hour. Public charging is for trips and top-ups, not daily use.
How much does an EV cost per kilometre to run?
For most EVs, home charging works out to a few cents per kilometre — commonly 2 to 6 cents depending on the tariff and the car's efficiency. At 20 kWh per 100 km and 30c/kWh, that is 6 cents per kilometre.
Why does my EV charging cost more than expected?
Common reasons are charging at peak rates, charging losses, a high flat tariff, or relying on public charging. Cold weather can also reduce battery efficiency. Check the tariff, the schedule and where the energy is coming from.
Sources and further reading
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