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Sauna Running-Cost Calculator
What a sauna costs to run each month at your electricity rate, with a 6 vs 8 vs 9 kW comparison.
How it is calculated
- kWh/mo = kW × (heat-up + session hours) × sessions/week × 4.33.
- Cost = kWh × your rate.
- Real bills run ~50–70% of this once up to temperature (element duty cycle).
Why your bill will differ
This figure is a ceiling, not a meter reading. The heater draws full power warming up, then the thermostat cycles the elements on and off to hold temperature, so the back half of a session uses far less than the rated kW. A well-insulated room and a closed door during pre-heat shrink the number further; a leaky room and a long pre-heat push it up.
Notice in the comparison that a bigger heater does not cost proportionally more to run. A 9 kW unit draws more while heating, but it reaches temperature faster and then idles the same as a smaller one, so for short sessions the monthly difference is small. Size on the room, not the power bill, then confirm the circuit.