The Numbers
What does a sauna cost to run? Work out your cost per session
A sauna's running cost is heater kilowatts times your electricity rate times the hours you sit. We work it through, and an electric session comes to cents.
By Adam Bognar, Editor
Running an 8 kW electric sauna heater for 30 minutes costs about $0.38 at the average US electricity rate, so five sessions a week come to roughly $8 a month. We worked the same numbers for infrared cabins and wood-fired stoves. The electric bill is the most common objection we hear, and it almost always rests on a guess that's several times too high. The math takes three numbers, and you can skip ahead and plug your own into the calculator below.
Try it with your numbers
Your sauna, your electricity rate
Per session
38¢
Per month
$8.34
Per year
$100
Assumes the heater averages 60% of rated draw across a session (full power heating up, cycling to hold temperature). Preheat you're not present for is included in that factor. These are estimates. Your insulation, climate, and habits all move the number.
The formula multiplies heater power by your time and rate
Running cost per session = heater power (kW) × session hours × your electricity rate ($/kWh) × a duty-cycle factor. The duty-cycle factor matters because a heater draws full power while it heats up and then cycles on and off to hold temperature. Over a session it averages roughly 50–65% of its rated draw. We'll use 0.6 as a reasonable middle estimate.
| Setup | Draw and session | Duty-cycle factor | Cost per session | Five sessions a week |
|---|---|---|---|---|
| 8 kW electric hot-rock heater, US average rate ($0.16/kWh) | 8 kW for 30 minutes | 0.6 | About $0.38 | About $8 a month |
| 8 kW electric hot-rock heater, high-rate state ($0.30/kWh) | 8 kW for 30 minutes | 0.6 | About $0.72 | About $16 a month |
| 2 kW infrared cabin ($0.16/kWh) | 2 kW for 45 minutes | 0.7 | About $0.17 | About $4 a month |
| Wood stove | 10 to 15 lbs of firewood | n/a | $1 to $3 | $22 to $65 a month |
Electricity is priced at the US average residential rate of about 16 to 17 cents per kWh (EIA, 2025). The duty-cycle factor accounts for a heater cycling on and off once the room is at temperature.
An electric hot-rock sauna costs about $0.38 a session
Take an 8 kW heater and a 30-minute session, which is 0.5 h including a bit of preheat you're present for, at the US average residential rate of about 16–17 cents per kWh. That's 8 × 0.5 × 0.16 × 0.6 ≈ $0.38 per session. Sauna five times a week and you're at roughly $8 a month. Even in a high-rate state at 30 cents/kWh, five sessions a week come to about $16 a month.
Where to buy
Harvia Heaters & Stoves
Harvia Cilindro PC80E 8kW Electric Sauna Heater
“Stone packed around the elements lets this tower make about as much steam as a home electric heater can.”
Infrared cabins cost less to run than hot-rock saunas
Infrared cabins draw less, often 1.6–2.8 kW. Sessions run longer at 45 min, and the lower power still wins. A 2 kW cabin for 45 minutes works out to 2 × 0.75 × 0.16 × 0.7 ≈ $0.17 per session. The duty-cycle factor is higher because infrared panels spend more of the session at full draw, and the cost still comes to a few dollars a month.
Where to buy
Dynamic Saunas Infrared Saunas
Dynamic Saunas Barcelona 1-2 Person Low EMF Far Infrared Sauna
Sun Home Saunas Infrared Saunas
Sun Home Solstice 2-Person Infrared Sauna
“A dedicated 120V/20A outlet runs this two-person infrared cabin.”
Dynamic Saunas Barcelona 1-2 Person Low EMF Far Infrared Sauna. Dynamic Saunas photography.
See the specifications and priceWood-fired saunas trade the electric bill for firewood
A single wood-fired session burns roughly 10–15 lbs of wood. At typical seasoned-hardwood prices the wood often costs $1–$3 a session. That's more than electric, but the stove doesn't depend on the grid and there's no electrician's bill up front. Count the chimney as a one-time cost when you compare.
Where to buy
The 240V circuit costs more than years of electricity
For an electric sauna, the dedicated 240V circuit often costs $600–$2,500 installed, and it usually adds up to more than years of electricity. The running cost rarely deserves the worry. Size the heater right and insulate the room, and each session's energy cost stays in loose-change territory.
Common questions
- How much does it cost to run a sauna per month?
- For near-daily use (5 sessions a week), most home saunas cost between $8 and $20 a month in electricity at typical US rates. Electric hot-rock heaters land around $8–16 and infrared often under $10. Wood-fired heat replaces the electric bill with firewood at roughly $1–3 per session.
- Does preheating cost a lot?
- No. A sauna heater draws full power while it preheats, but that only lasts 30–45 minutes for a traditional room and less for infrared. It's already baked into the duty-cycle factor in our formula. A Wi-Fi controller that preheats only when you'll use the sauna avoids waste.
- What's the biggest hidden cost?
- The dedicated 240V circuit is the biggest hidden cost of an electric sauna. It's a real electrical job that can run $600–$2,500 depending on the panel and the run. You pay it once, and it usually exceeds years of electricity, so budget for it before you buy the heater.
Sources
- 1.Electric Power Monthly: Average Price of Electricity to Ultimate Customers. U.S. Energy Information Administration, 2025.
- 2.NFPA 70: National Electrical Code (NEC). National Fire Protection Association, 2023.
- 3.Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events. JAMA Internal Medicine, 2015.
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