One of the most practical ways to understand the real cost of driving an electric vehicle is to calculate the EV charging cost per 100km and compare it directly to petrol. In 2026, with Australian petrol prices hovering between $1.80 and $2.20 per litre and electricity rates varying by state, the difference in fuel costs per kilometre is striking — and it's one of the strongest arguments for making the switch to electric.
How to Calculate EV Charging Cost Per 100km
EV energy consumption is measured in kilowatt-hours per 100 kilometres (kWh/100km) — equivalent to litres per 100km for petrol cars. Most popular EVs in Australia consume between 14 and 22 kWh/100km depending on the vehicle size, driving speed, and conditions.
The formula for charging cost per 100km is: kWh/100km × electricity rate ($/kWh)
For example, a Tesla Model 3 RWD consuming 15 kWh/100km charged at 30c/kWh home rate: 15 × $0.30 = $4.50 per 100km.
EV Charging Cost Per 100km by State
Home charging rates vary by state and tariff. Here's the charging cost per 100km for a mid-size EV (15 kWh/100km) in each Australian state, at typical home electricity rates:
| State | Typical Home Rate | Cost/100km (15 kWh) | Off-Peak Rate | Off-Peak Cost/100km |
|---|---|---|---|---|
| South Australia | 38c/kWh | $5.70 | 16c/kWh | $2.40 |
| New South Wales | 32c/kWh | $4.80 | 15c/kWh | $2.25 |
| Victoria | 30c/kWh | $4.50 | 15c/kWh | $2.25 |
| Queensland | 30c/kWh | $4.50 | 18c/kWh | $2.70 |
| Western Australia | 31c/kWh | $4.65 | 18c/kWh | $2.70 |
| ACT | 27c/kWh | $4.05 | 16c/kWh | $2.40 |
| Tasmania | 28c/kWh | $4.20 | 17c/kWh | $2.55 |
EV Charging Cost Per 100km With Solar
If you charge your EV from excess solar generation during the day (rather than from the grid), the effective electricity cost is the feed-in tariff you give up — typically 5–10c/kWh — rather than the full grid rate. In most cases, EV owners with solar consider daytime solar charging to be effectively free.
| Charging Source | Cost Per 100km (15 kWh EV) | Annual Fuel Cost (15,000km/year) |
|---|---|---|
| Home (flat rate, national avg 31c) | $4.65 | $698 |
| Home (off-peak rate, ~16c) | $2.40 | $360 |
| Solar (daytime charging) | $0.75–$1.50 | $112–$225 |
| Public DC fast charger (~65c/kWh) | $9.75 | $1,463 |
The contrast between solar charging and public DC fast charging is stark. Home solar charging is the cheapest option by far — close to 14 times cheaper than using public fast chargers as your primary source. This is why home charging infrastructure matters so much to the economics of EV ownership.
Petrol Cost Per 100km: The Comparison
A typical petrol car in Australia consumes 8–12 litres per 100km. At current petrol prices of $1.85–$2.10 per litre (capital city average, April 2026), the fuel cost is:
| Vehicle Type | Fuel Consumption | Cost/100km at $1.95/L | Annual Cost (15,000km) |
|---|---|---|---|
| Small petrol car (e.g. Toyota Corolla) | 7.5L/100km | $14.63 | $2,194 |
| Mid-size petrol car (e.g. Mazda CX-5) | 9.0L/100km | $17.55 | $2,333 |
| Large SUV/ute (e.g. Ford Ranger) | 11.5L/100km | $22.43 | $3,364 |
| Mid-size EV (home charging, avg rate) | 15 kWh/100km | $4.65 | $698 |
| Mid-size EV (off-peak charging) | 15 kWh/100km | $2.40 | $360 |
The savings are unambiguous. Switching from a mid-size petrol car to an EV charged at home saves $1,600–$2,600 per year in fuel costs alone. Over a 10-year ownership period, that's $16,000–$26,000 — a substantial contribution toward the purchase price of the EV itself.
Popular EV Energy Consumption Figures
Not all EVs are equal in efficiency. Here's a comparison of popular Australian EV models and their real-world energy consumption:
| EV Model | Real-World Consumption (kWh/100km) | Home Charging Cost/100km (31c) |
|---|---|---|
| Tesla Model 3 RWD | 14–16 | $4.34–$4.96 |
| BYD Seal RWD | 15–17 | $4.65–$5.27 |
| MG4 EV (Standard) | 15–18 | $4.65–$5.58 |
| Hyundai IONIQ 6 RWD | 13–15 | $4.03–$4.65 |
| BYD Atto 3 | 16–19 | $4.96–$5.89 |
| Tesla Model Y AWD | 17–20 | $5.27–$6.20 |
Calculate Your Own EV Fuel Cost
The right answer depends on your driving distance, charging habits, electricity rate, and which EV you're comparing against your current petrol car. Use our EV Home Charging Cost Calculator to enter your specific vehicle, electricity tariff, and annual kilometres — and get a personalised cost per 100km figure with a direct comparison to petrol.