Sauna running cost calculator
Example: 6 kW heater, 4 sessions a week, 20 minutes plus 30 minutes preheat
- Per session
- $0.92
- Per month
- $15.87
- Per year
- $190.42
- Energy per session
- 5 kWh
The formula
- Hours of full power per session = preheat minutes / 60 + session minutes / 60 x on-time %.
- kWh per session = heater kW x hours of full power.
- Cost per session = kWh x your rate in dollars.
- Yearly cost = cost per session x sessions per week x 52. Monthly cost = yearly / 12.
Default rate: 18.31 cents per kWh, the U.S. residential average from the EIA Electric Power Monthly(checked Oct 2026). Your bill shows your actual rate.
A sauna can cost less to run each month than most people expect. Here’s how to work out your real number from your heater’s kW and your electric rate.
How to use it
Pick a sauna or heater, or type the heater’s kW from its spec sheet. Your electric bill lists your rate in cents per kWh. The default is the current U.S. residential average.
Why the estimate runs high
The calculator assumes the heater runs at full power during preheat and, by default, for the whole session. Thermostats cycle the heater off once the room is hot, so lower the on-time to match your heater if you know it.
Next steps
Size your heater with the sauna heater size calculator, compare totals in the home sauna cost guide, or start at the home sauna buyer’s guide.