How much does an outdoor sauna cost to run?
The answer depends on your heater, how long it's on and what your utility charges per kilowatt-hour. Here's the formula, the real power ratings, and a calculator you can fill in with your own numbers.
Image: Sun Home.
The formula
Cost per session = heater kilowatts × hours the heater is actually on × your price per kWh.
Your price per kWh is on your electricity bill. It varies a lot by state and utility, so we don't quote an average here. Use your own.
What the ratings tell you
| Model | Rated power | Source of the number |
|---|---|---|
| Solaris 4 (traditional) | 6 kW heater | HUUM DROP 6 kW, per Sun Home's listing |
| Solaris 6 (traditional) | 9 kW heater | HUUM HIVE Mini 9 kW, per Sun Home's listing |
| Luminar 2-Person (infrared) | Up to 4.8 kW* | 240V × 20A circuit |
| Luminar 5-Person (infrared) | Up to 7.2 kW* | 240V × 30A circuit |
*These are the most the circuit can carry, not what the sauna draws. We haven't seen a wattage published for the Luminar heaters, so ask Sun Home for the actual draw before you rely on an estimate. Listings as of October 13, 2026.
Worst-case cost per hour
This is the heater running flat out for a full hour, so it's a ceiling. Traditional heaters switch on and off to hold temperature, so most sessions will cost less than this.
| Heater | At $0.10/kWh | At $0.20/kWh | At $0.30/kWh |
|---|---|---|---|
| 6 kW | $0.60 | $1.20 | $1.80 |
| 9 kW | $0.90 | $1.80 | $2.70 |
The three rates are examples for the arithmetic, not averages for any state.
Try your own numbers
Costs the electricity math misses
- Installing the circuit. Every outdoor model needs a dedicated 240V circuit from a licensed electrician. Get a quote first, since it can be a one-time cost larger than years of power.
- Heat-up time. We don't have a verified heat-up time for these models. Ask the maker, then plug that into the calculator.
- Cold weather. An outdoor sauna in winter may take longer to heat, which raises the hours.
- Maintenance. Wood and cover care are small, but check each model's care instructions.
Compare the four outdoor saunas
Planning the spot? See how much space an outdoor sauna needs.
Not sure which type? Read infrared vs traditional saunas.