What does heating the sauna cost on spot electricity?
An electric sauna stove is one of the largest single power users in a home. The calculator shows what a sauna costs today and when it is cheapest.
Checked by Radif Partners · Editorial policy · Method and sources
According to Motiva, a one-off electric sauna stove is by far the largest single electrical appliance in a home, and over half of its electricity goes on preheating. A 6 kW stove uses about 9.0 kilowatt-hours over an hour and a half of heating and bathing. In Helsinki, on Helen Sähköverkko’s general transfer and a spot contract with a 0.51 c/kWh margin, such a sauna costs €0.84 at the day’s cheapest start (04:30) and €1.18 at the dearest (17:00). At the day’s average price it costs €1.02. In Järvi-Suomen Energia’s area, where transfer is dearer, the same sauna costs €1.09 at the average price. Two saunas a week come to about €106 a year in Helsinki. Enter your stove’s power, heating time, operator and contract below to see today’s or tomorrow’s cheapest and dearest start and the annual cost.
Electric sauna stove: cheapest run today
€0.84
9.00 kWh over 1.50 h
| Cheapest start 04:30 | €0.84 |
| Dearest start 17:00 | €1.18 |
| At the day’s average price | €1.02 |
| Per year, 2 times a week at average price | €106 |
Exchange prices published for 17 October 2026, FI bidding zone, source Nord Pool.
Assumptions
Energy is spread evenly over the quarters of the run. Price = spot + margin (or fixed price) + transfer fee + electricity tax, all incl. 25.5% VAT. Real use varies with the appliance, programme and temperature. Method and sources
The cost of a sauna with two stoves
| Stove | Energy | Cheapest start | At average price | Dearest start |
|---|---|---|---|---|
| 6 kW, 1.5 h | 9.0 kWh | €0.84 (04:30) | €1.02 | €1.18 (17:00) |
| 9 kW, 1.5 h | 13.5 kWh | €1.27 (04:30) | €1.53 | €1.77 (17:00) |
The table uses the exchange prices of the day the page was updated and refreshes daily. Your stove’s power is on its rating plate, and it is usually sized to the room’s volume. The larger the room and the poorer the insulation, the longer the stove must heat.
What a sauna’s cost is made of
A sauna has the same price parts as any other electricity: exchange price and margin, transfer fee and electricity tax. On general transfer, transfer and tax cost the same at every hour, so in Helsinki they account for €0.69 of every sauna whenever you heat it. Timing only saves on the exchange price. On time-of-day transfer night transfer is cheaper too, and on seasonal transfer winter weekdays are dearer.
Five ways to a cheaper sauna
- Heat the sauna once for the whole family, since preheating takes over half the energy.
- Keep it at 70–80 °C: heating to 100 °C uses 20–30% more, according to Motiva.
- Pick the cheapest start time in the calculator if you are on a spot contract.
- Do not leave the stove on after bathing.
- Avoid heating the sauna while the car charges if your operator has a power fee.
Motiva’s energy-efficient sauna advice has more. See the car charging and washing machine calculators for other appliances.