Key facts
- Cost per session = heater kW x hours on x your rate per kWh.
- EIA July 2026 residential averages: WA 14.71 cents, OR 15.97 cents, US 18.31 cents per kWh.
- A 6 kW heater for one hour at full draw: $0.88 WA, $0.96 OR, $1.10 US.
- Thermostats cycle heaters off once the room is hot, so real use is usually below these figures.
- Infrared cabins we checked draw 1,800 to 3,840 W max (Sunlighten specs).
Cost per session and per month
Assumes the heater draws its full rating for one hour per session and 13 sessions a month (three a week). Both are our assumptions, chosen as a ceiling.
| Heater | kWh per session | Washington | Oregon | US average |
|---|---|---|---|---|
| Infrared, 1,800 W (120V) | 1.8 | $0.26 / $3.44 mo | $0.29 / $3.74 mo | $0.33 / $4.28 mo |
| Infrared, 2,400 W (120V) | 2.4 | $0.35 / $4.59 mo | $0.38 / $4.98 mo | $0.44 / $5.71 mo |
| Infrared, 3,840 W (240V) | 3.84 | $0.56 / $7.34 mo | $0.61 / $7.97 mo | $0.70 / $9.14 mo |
| Traditional, 4.5 kW | 4.5 | $0.66 / $8.61 mo | $0.72 / $9.34 mo | $0.82 / $10.71 mo |
| Traditional, 6 kW | 6 | $0.88 / $11.47 mo | $0.96 / $12.46 mo | $1.10 / $14.28 mo |
| Traditional, 8 kW | 8 | $1.18 / $15.30 mo | $1.28 / $16.61 mo | $1.46 / $19.04 mo |
| Traditional, 9 kW | 9 | $1.32 / $17.21 mo | $1.44 / $18.68 mo | $1.65 / $21.42 mo |
Rates: EIA Electric Power Monthly, Table 5.6.A, July 2026 residential averages. Infrared wattages are Sunlighten maximum ratings, listed in our infrared vs traditional guide. Your utility's rate, including any tiered or time-of-use pricing, will differ.
Work out your own number
- Find your heater's kW rating on its label or manual. Infrared cabins list watts; divide by 1,000.
- Time a typical session from switch-on to switch-off, including preheat.
- Multiply kW by hours. That is your ceiling in kWh, since the heater cycles once hot.
- Multiply by the per-kWh rate on your bill, then by sessions per month.
What actually moves the bill
- Preheat time. Most of the full-power running happens here. Cold weather and a cold room stretch it.
- Heater sizing. Match the heater to room volume per the maker's chart.
- Heat loss. Door seals, roof insulation and a dry foundation all shorten heating time (our reasoning, not a measured figure).
- Frequency. Daily use is about 2.3 times the three-a-week monthly figures above.
Related guides
- Rocky Mountain Power time of use with a hot tub or sauna in Utah
- Sauna heater breaker and wire size
- Outdoor sauna install cost
- Outdoor saunas in rainy climates
- Cold plunge chiller cost to run
- Sauna collection
Frequently asked questions
How much does it cost to run a home sauna?
With the heater drawing its full rating for one hour per session, a 6 kW traditional heater uses 6 kWh. At EIA July 2026 residential rates that is about 88 cents in Washington, 96 cents in Oregon and $1.10 at the US average. Three sessions a week (about 13 a month) comes to roughly $11 to $14 a month. Real use is usually lower because the thermostat cycles the heater.
Is an infrared sauna cheaper to run than a traditional sauna?
Per hour, yes, because the elements draw less power. A 120V infrared cabin rated at 1,800 W uses 1.8 kWh in an hour at full draw, about 26 cents in Washington. A 6 kW traditional heater uses 6 kWh, about 88 cents. The difference is real but small in dollars, so choose on placement, feel and wiring rather than running cost.
How do I calculate my sauna's running cost?
Multiply the heater's kilowatt rating by the hours it is on, then by the rate on your power bill. Example: 8 kW for 1 hour is 8 kWh. At Oregon's July 2026 average of 15.97 cents per kWh, that is about $1.28. For a monthly figure, multiply by your sessions per month. Use your own rate, since utilities differ widely within a state.
Why is a one hour figure an overestimate?
A sauna heater runs at full power while it heats the room, then a thermostat switches it on and off to hold temperature. Charging the full rating for the whole hour assumes it never cycles off. That makes our table a ceiling, not a typical bill. A short preheat in a well insulated room costs less; a long preheat on a cold, windy evening costs more.
Does an outdoor sauna cost more to run in the Pacific Northwest?
Likely a bit more in winter, though we have no measured figure. Cold air and damp walls mean a longer preheat, and every extra minute at full power adds cost. Our reasoned tips: a tight door seal, an insulated roof, keeping the sauna off wet ground and right-sizing the heater to the room. See our rainy-climate sauna guide.
Does a bigger heater cost more to run?
It draws more per hour, but it can reach temperature faster in a room it is sized for. An oversized heater cycles more, and an undersized one runs longer. The meaningful saving comes from matching the heater to the room volume per the maker's chart, not from buying the smallest heater. Follow your heater maker's sizing table.
What does a wood-fired sauna cost to run?
No electricity for heat, but you pay for firewood instead. We have not priced firewood by region, so we do not give a figure. Wood-fired saunas also face burn ban rules in parts of Washington. See our Washington burn ban guide before choosing wood heat in Puget Sound counties.
Will a sauna raise my power bill a lot?
For most households, no. Even a 9 kW heater at full draw for an hour, three times a week, works out to about $17 a month in Washington and $21 at the US average at July 2026 rates. Daily use roughly doubles those figures. The larger cost is usually installing a 240V circuit, covered in our install cost guide.
Keep reading
Browse our saunas collection, see all guides, or ask us a question about your project.