Silo

Saunas

Almost every sauna purchase stalls on the same thing: the electrical supply. The room size decides the heater, the heater decides the circuit, and the circuit decides whether the project is a weekend or an electrician’s invoice. These pages work that chain in the order you actually hit it.

Disclosure. This page contains affiliate links; we may earn a commission on qualifying purchases at no cost to you. As an Amazon Associate I earn from qualifying purchases. Every figure on this site is reproduced from a published manufacturer manual, standard or government document and linked so you can check it yourself. We do not own or test the products we write about, and we say so on every page rather than implying otherwise.
Sauna 240V vs 120V: which one do you actually needA 120V circuit carries about 1.4 kW continuously. Every traditional heater starts at 3 kW. The arithmetic that decides which side of the line your room is on. Can you plug an infrared sauna into a regular outlet?Usually yes, if the circuit is dedicated. The failure mode is almost never the sauna — it is what else is sharing the breaker. What size breaker and wire for a 6, 8 or 9 kW heaterThe manuals and the code formula disagree at every size. Both tables, and the reason they differ. How much does a home sauna cost to run?About 975 kWh a year for a 6 kW heater used three times a week — which is 128 dollars in Nevada and 514 in Hawaii. All fifty-one states, and the reason an average rate is the wrong tool for the job.

Sauna heater size calculator

Enter your room and it returns the kW figure Harvia’s published rule produces, then shows what the manuals specify for breaker and wire at that size next to what the code formula gives — because the two do not agree.

Open the calculator

And then there is the bill

A heater's rating is a purchase decision; what it costs to run is a different one, and it varies by a factor of four across the country for identical equipment used identically.

Running cost by state