Put simply, an electric car uses energy measured in kilowatt-hours (kWh). Think of it like litres for petrol or diesel, just with volts instead of fumes. For context, a litre of diesel holds roughly 10 kWh of energy.
So the cost of a charging session depends on how many kWh you add.
On top of that neat little equation, there are extras that can nudge the price up: session fees, idle (overstay) charges, and different tariffs depending on time of day, location and demand.
Say your car has a 75 kWh battery.
If electricity costs €0.35 per kWh, a full charge would be €26.25 — that’s 75 kWh × €0.35/kWh. Straightforward enough.
Charging at home is usually the cheapest way to fill up. Expect roughly €0.25 to €0.45 per kWh. It can be even cheaper with rooftop solar or a flexible tariff.
With the right setup, a home wallbox is the most cost-effective option and a no-brainer for homeowners.
Public charging generally costs more than charging at home. Typical prices range from about €0.45 to €0.65 per kWh, and can be higher.
Slower AC chargers (3.7 kW to 22 kW) are often run by local municipal utilities, who sometimes offer cheaper ad hoc rates at their own posts — and even better deals for their electricity customers.
Rapid chargers, by contrast, tend to be pricier. Expect anything from around €0.35 up to €1.00 per kWh. It’s worth checking tariff comparison sites to find a good-value membership or charging card.
Some rapid-charging networks also offer discounted monthly subscriptions. A quick look at the operator’s website can pay off.
Public networks often apply idle (overstay) fees to stop fully charged cars hogging the space.
You’ll be charged if the car isn’t moved once charging finishes. Some providers apply idle fees after a fixed window — say three to four hours — regardless of charge status.
Costs vary widely and can be up to €1.00 per minute, though many cap the total at around €12–€20.
A few slower public chargers waive idle fees overnight, but that’s the exception rather than the rule.
Back to our Tesla Model 3. This time the battery’s nearly full, so we only add 10 kWh at €0.65 per kWh. That’s €6.50 for energy.
At Tesla Superchargers, idle fees start at €0.50 per minute. If we unplug 10 minutes after charging completes, that’s €5.00 in idle fees — so €11.50 in total.
Some providers add a session (or transaction) fee on top of the energy cost.
This can range from €0.35 to €10.00 and is charged as soon as you plug in.
It’s rare, but not unheard of: pricing per minute connected. The clock runs while your car is plugged in. Rates can start around €0.01 per minute and go up from there.
Whether it’s fair depends on your view, but it does muddy the waters.
It also makes costs harder to predict, because charging time depends on power delivered. In other words, you’re relying on the charger to deliver the advertised speed — and not quietly throttle it.
Let’s say we add 11 kWh on an 11 kW charger. That takes one hour. The per-minute rate is €0.04 and the energy price is €0.23 per kWh.
That’s €2.53 for energy and €2.40 for time — €4.93 in total.
Worked back, that’s effectively €0.45 per kWh.
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