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In Harvia’s named example, a 2-hour session with a 6 kW heater uses about 7 to 9 kWh. At the July 2026 U.S. average residential rate of 18.31 cents per kWh, that is about $1.28 to $1.65 (own calculation).
Your bill depends on your rate, heater size, insulation and how long the heater stays on. Tylo publishes a separate one-hour figure for a home heater.
Every figure below comes from a source we opened, and we have not built or tested any sauna. For setup context, see planning and building a home sauna.
The short answer
- Harvia’s example: about 7 to 9 kWh for a 2-hour session with a 6 kW heater in an insulated family sauna.
- Harvia also gives about 9 to 13 kWh for a larger 8 kW heater over the same two hours.
- Tylo’s energy page gives about 5 kWh for one hour of bathing with what it calls a 6 kWh heater. Heaters are rated in kW, not kWh, so we read that as a 6 kW heater.
- At the July 2026 U.S. average of 18.31 cents per kWh, 7 to 9 kWh costs about $1.28 to $1.65 (own calculation).
- Multiply your own kWh estimate by the rate on your bill. Do not treat kW rating times hours as the real cost.
How do you calculate the cost to run a sauna?
Multiply kilowatt-hours used by your price per kilowatt-hour. That is the whole formula.
Do not multiply the heater’s kW rating by the hours it is switched on. Both Harvia and Tylo say heat-up uses most of the power, then the thermostat cuts back.
Step by step
- Find your residential rate on your electric bill, in cents or dollars per kWh.
- Estimate kWh per session from your heater maker, or use the Harvia and Tylo examples below as a starting point.
- Multiply: kWh x rate. Example at the July 2026 U.S. average: 8 kWh x $0.1831 = $1.46 (own calculation).
- Multiply by sessions per year for an annual figure.
What do manufacturers say about kWh use?
We opened energy pages from Harvia and Tylo. Other heaters will differ. Treat these as named examples, not a universal rule.
Harvia’s 6 kW and 8 kW examples
Harvia’s energy FAQ describes a traditional Finnish family sauna for 3 to 4 people with a 6 kW heater. It says the first hour uses about 4 to 5 kWh, and the next hour about 3 to 4 kWh.
Together that is about 7 to 9 kWh for two hours, in an insulated sauna with a correctly sized heater.
On a separate cost page, Harvia gives the same 7 to 9 kWh for a 6 kW heater. For an 8 kW heater it gives about 9 to 13 kWh over two hours.
Harvia also says the heater runs at full power for about the first 30 to 40 minutes. After that, power is about 50% of maximum to hold temperature.
Tylo’s one-hour example
Tylo’s energy page gives about 5 kWh for one hour of bathing with what it calls a 6 kWh heater. Heaters are rated in kW, not kWh, so we read that as a 6 kW heater.
For two people bathing 40 minutes, plus 20 minutes of heating, Tylo estimates about 2.5 kWh per person. Tylo also says heat-up can take up to 80% of capacity in the first hour.
What this costs
The table uses Harvia’s 7 to 9 kWh session example and EIA July 2026 residential rates. Dollar figures are our multiplications.
| Place | Rate (cents per kWh, July 2026) | One session, 7 to 9 kWh | One year, 1,092 to 1,404 kWh | One year, 780 kWh |
|---|---|---|---|---|
| U.S. average | 18.31 | $1.28 to $1.65 | $200 to $257 | $143 |
| Louisiana | 12.72 | $0.89 to $1.14 | $139 to $179 | $99 |
| Texas | 15.88 | $1.11 to $1.43 | $173 to $223 | $124 |
| New York | 29.90 | $2.09 to $2.69 | $327 to $420 | $233 |
| California | 33.61 | $2.35 to $3.02 | $367 to $472 | $262 |
| Hawaii | 48.00 | $3.36 to $4.32 | $524 to $674 | $374 |
Annual columns follow Harvia’s published kWh totals for three sessions a week. The 1,092 to 1,404 kWh range is two hours on per session. The 780 kWh figure is Harvia’s “smarter use” example.
At the July 2026 U.S. average, Harvia’s 8 kW example of 9 to 13 kWh costs about $1.65 to $2.38 per session (own calculation). Tylo’s 5 kWh one-hour figure costs about $0.92 at the same rate (own calculation).
What makes a sauna cost more or less to run?
Four things move the bill most: your rate, heater size, how long it stays on, and how well the room holds heat.
Your electricity rate
The EIA’s July 2026 U.S. average residential price was 18.31 cents per kWh, up from 17.45 cents in July 2025. State averages in the same table range from 12.72 cents in Louisiana to 48.00 cents in Hawaii.
The EIA calculates average revenue per kilowatt-hour as a proxy for price. Check your own bill, and refresh the table after each monthly release.
Heater size and session length
A larger heater and a longer “on” time use more kWh. Harvia’s 8 kW example sits above its 6 kW example for the same two-hour pattern.
Harvia says going in as soon as the room is ready can cut annual use in its example. At three sessions a week, that example falls to about 780 kWh.
Insulation and outdoor saunas
Harvia’s kWh figures assume an insulated sauna with a correctly sized heater. A poorly insulated or outdoor room can use more energy to reach and hold temperature.
We did not find a separate published outdoor kWh figure from these makers for this article.
UK and EU readers
Use the same kWh examples, then multiply by your local rate. We opened Eurostat and Ofgem pages today.
Eurostat reports an EU average household electricity price of €0.2896 per kWh in the second half of 2025. At that rate, 7 to 9 kWh is about €2.03 to €2.61 (own calculation).
Ofgem’s Direct Debit price cap for 1 October to 31 December 2026 averages 26.32 pence per kWh for electricity. At that rate, 7 to 9 kWh is about £1.84 to £2.37 (own calculation).
Your tariff, standing charge and region will differ. Check your bill or the current Ofgem and Eurostat releases.
When to call a professional
Running cost is a bill question. Wiring a new heater is not. Have a licensed electrician size the circuit to the heater nameplate and your local code.
We are not electricians or inspectors. Ask your utility or a licensed electrician if your panel and rate plan can support the load.
Common questions
Harvia’s named 6 kW example uses about 7 to 9 kWh over two hours. Its 8 kW example uses about 9 to 13 kWh over two hours. Tylo’s energy page gives about 5 kWh for one hour of bathing with what it calls a 6 kWh heater. Heaters are rated in kW, not kWh, so we read that as a 6 kW heater.
There is no single hourly price. At the July 2026 U.S. average of 18.31 cents per kWh, Tylo’s 5 kWh one-hour figure is about $0.92 (own calculation). Your rate and heater will change that.
Multiply your session cost by sessions per month. Three sessions a week at Harvia’s 7 to 9 kWh example is about 84 to 108 kWh per month. At the July 2026 U.S. average that is about $15 to $20 (own calculation).
At U.S. average rates, Harvia’s 6 kW example is a few dollars per session. In high-rate states or with a larger heater, the same pattern costs more. Compare it to your own bill.
Harvia’s own examples put an 8 kW heater at about 9 to 13 kWh over two hours. That sits above the 7 to 9 kWh for its 6 kW example. A heater that is too small can also run longer to heat the room.
Use a correctly sized heater, wait to start until you will actually bathe, and keep sessions shorter once the room is ready. Harvia’s smarter-use example cuts annual kWh in its own figures. Check for a cheaper time-of-use rate on your plan.
Next steps
- Planning and building a home sauna: site, power, ventilation and permits
- Sauna heaters: kilowatts, brands and what your electrician needs
- Sauna ventilation requirements: how much air a sauna needs
- Home saunas: barrel, cabin and infrared types
Sources
- Harvia FAQ: energy consumption of sauna bathing: 6 kW example, 7 to 9 kWh, annual 1,092 to 1,404 kWh and 780 kWh
- Harvia: the cost of heating a sauna is less than you think: 6 kW and 8 kW session examples
- Tylo: 5 tips for energy-efficient sauna bathing: about 5 kWh for one hour with what it calls a 6 kWh heater (heaters are rated in kW, not kWh; we read that as 6 kW)
- EIA Electric Power Monthly, Table 5.6.A: July 2026 residential prices by state
- EIA Electricity Monthly Update, end-use: July 2026 residential average context
- Eurostat news: EU household electricity prices stable in 2025: second half 2025 EU average
- Eurostat Statistics Explained: electricity price statistics: €0.2896 per kWh figure
- Ofgem: energy price cap unit rates and standing charges: 1 October to 31 December 2026 Direct Debit electricity unit rate
- House of Commons Library briefing CBP-9714: July to September 2026 Direct Debit electricity unit rate context
All sources checked 5 October 2026.