For a simple upper-bound style estimate, multiply heater power in kilowatts by the hours it is assumed to draw power, then multiply by your electricity unit rate. Real consumption can differ as thermostatic controls cycle.
The core calculation
Estimated cost = heater kW × assumed powered hours × electricity price per kWh. Keep heat-up time and session time visible so you can test different habits.
Why the result is approximate
Ambient temperature, insulation, ventilation, door opening, set temperature, heater controls, warm-up behaviour and auxiliary loads can all affect measured energy use.
Use your own tariff
Read the unit rate from your bill or supplier information and update it when the tariff changes. Do not confuse the unit rate with the daily standing charge.
Frequently asked questions
Does a sauna heater draw its full rating for the whole session?
Not necessarily. Controls may cycle the heater after warm-up. The calculator is an assumptions tool, not a meter reading.