A home sauna used three to four times per week typically adds around $15 to $60 to your monthly electric bill, depending on your heater's wattage, how long you run it, and what your utility charges per kilowatt-hour.
You’re thinking about putting a sauna in your home, or maybe you already have one and noticed the utility bill creeping up. Either way, you want the straight numbers before you commit or start worrying.
Let’s cut through the vague estimates and give you something you can actually use.
The short answer: A typical home sauna used 3-4 times per week will add roughly $15 to $60 to your monthly electric bill, depending on your sauna type, local electricity rates, and how long you stay in.
That range is wide because the variables matter. Let me walk through them so you can estimate your own number.
What determines your sauna’s electricity use
Three things drive the cost: the heater’s wattage, how long it runs, and how much your utility charges per kilowatt-hour (kWh).
Most home sauna heaters fall between 4.5 kW and 9 kW. A 6 kW heater is common for a 4-person sauna. A 9 kW unit is typical for larger rooms or faster heat-up times.
Electricity rates in the U.S. average around $0.12 to $0.23 per kWh as of 2025, but yours could be higher or lower depending on where you live. Hawaii pays around $0.40. Louisiana pays closer to $0.10.
Here is the math for a typical scenario:
- 6 kW heater
- 30-minute warm-up time (heater running full power)
- 20-minute session (heater cycles on and off to maintain temperature)
- 4 sessions per week
The warm-up pulls about 3 kWh per session (6 kW × 0.5 hours). The session itself pulls roughly 1 kWh (6 kW × 0.33 hours × 50% duty cycle). That is 4 kWh per session. At 16 sessions per month, you are looking at 64 kWh. At the national average of $0.16/kWh, that is about $10.24 per month.
Now add the reality that most people let the sauna run longer, heat up a bigger room, or use a higher-wattage heater. That is how you get to the $15 to $60 range.
Infrared vs. traditional: which costs more?
This is where most online advice gets fuzzy.
Traditional (Finnish) saunas use a heater that heats rocks. They pull full wattage during warm-up, then cycle on and off. A typical 6 kW Finnish sauna running for 45 minutes total (warm-up plus session) uses about 4.5 kWh per session.
Infrared saunas use lower-wattage heaters (1.5 to 3 kW typically) but run longer because they heat your body directly rather than the air. A 45-minute infrared session might use 1.5 to 2.5 kWh.
On the surface, infrared looks cheaper. But infrared sessions often run longer (people stay in 30-60 minutes versus 15-20 minutes for traditional), and the heat-up time is shorter because there is no rock mass to warm. The difference is real but smaller than most articles claim.
Practical takeaway: If you use both saunas 4 times per week, the traditional Finnish sauna will cost about $10-$20 more per month than an infrared unit. That gap narrows if you run the infrared longer.
What about the warm-up phase?
The warm-up is where most of the electricity goes. A Finnish sauna heater runs at full power for 30 to 60 minutes before the room reaches temperature. That is the expensive part.
Once the room is hot, the heater only kicks on briefly to maintain temperature. The duty cycle drops to 20-40% depending on insulation, room size, and how often you open the door.
One thing that matters more than most people realize: sauna insulation. A well-insulated sauna room with a vapor barrier and proper door seal will hold heat significantly better than a leaky one. That means the heater cycles less during your session. If you are building your own sauna, spend the extra money on insulation. It pays for itself in six months of lower electric bills.
How to estimate your own monthly cost
Grab your latest electric bill and find your rate per kWh. Then run this quick calculation:
- Find your heater’s wattage (check the spec plate or manual)
- Estimate your total weekly sauna hours (warm-up time plus session time)
- Multiply: (wattage ÷ 1000) × total weekly hours × 4.3 weeks × your rate
For example, a 6 kW heater running 3 hours total per week (including warm-up) at $0.16/kWh:
(6 × 3 × 4.3) × 0.16 = $12.38 per month
That is the upper estimate assuming the heater runs full power the entire time. Real-world use is lower because the heater cycles off once the room is hot.
A few things nobody tells you
Peak vs. off-peak rates matter. If your utility charges time-of-use rates, running the sauna at 6 PM when everyone else is cooking dinner and running AC costs more than running it at 9 PM. Some utilities offer off-peak rates that cut your cost by 30-50%. Check your plan.
The heater itself ages. Electric resistance heaters lose efficiency over time, especially if the elements corrode or the rocks degrade. A well-maintained heater from a reputable brand (Harvia, Tylo, Saunacore) will hold efficiency for years. Cheap units lose it faster.
Your sauna’s location affects cost. An outdoor sauna in Minnesota in January will cost more to heat than an indoor sauna in a climate-controlled basement. The heater has to overcome the temperature difference between the room and the outside. That can add 20-30% to your monthly cost in extreme climates.
The bottom line (not a cliché, just the facts)
If you are using a home sauna 3-4 times per week, expect to see $15 to $40 added to your monthly electric bill for a traditional Finnish sauna, or $10 to $25 for an infrared unit. That is less than a couple of takeout dinners or a single gym membership.
For the cost of a Netflix subscription, you get something that actually improves your cardiovascular health, reduces inflammation, and—based on that Finnish study I mentioned earlier—might add years to your life.
Worth it? That is your call. But now you have the numbers to make an informed decision.
If you are just starting with sauna, check your local electricity rates and your heater’s wattage before you build or buy. And if you have specific health conditions or concerns about heat exposure, talk to your doctor before starting a regular sauna routine.
Frequently asked questions
How much does it cost to run a home sauna each month?
For a traditional Finnish sauna used three to four times per week, expect to add roughly $15 to $40 to your monthly electric bill. An infrared unit running on the same schedule tends to cost a bit less, around $10 to $25 per month. The exact figure depends on your heater's wattage, your local electricity rate, and how long each session runs.
Do infrared saunas use less electricity than traditional saunas?
Infrared saunas do use lower-wattage heaters, typically 1.5 to 3 kW, compared to the 4.5 to 9 kW range common in traditional Finnish models. However, infrared sessions often run longer because people tend to stay in for 30 to 60 minutes rather than the 15 to 20 minutes typical of a traditional sauna. If you use both types four times per week, the traditional sauna will cost about $10 to $20 more per month, and that gap narrows if you run the infrared longer.
When does a home sauna use the most electricity?
The warm-up phase is where most of the electricity goes, since a Finnish sauna heater runs at full power for 30 to 60 minutes before the room reaches temperature. Once the room is hot, the heater only kicks on briefly to maintain heat, dropping to a duty cycle of around 20 to 40 percent. Good insulation with a vapor barrier and a proper door seal helps the heater cycle less during your session, which lowers your bill.
How do I calculate my own sauna electricity cost?
Find your heater's wattage on the spec plate or manual, then estimate your total weekly sauna hours including warm-up time. Multiply your heater's kilowatt rating by your weekly hours, then by 4.3 weeks, and then by your rate per kilowatt-hour. Keep in mind this gives an upper estimate, since the heater cycles off once the room is hot, so real-world costs will be a little lower.