Home sauna buying worksheet

Step 1. Size the room, then the heater

Heater output scales with room volume, not floor area: figure 1 kW of heater power for every 45 cubic feet, and add about 25 percent if the walls include concrete, tile or glass, because those surfaces absorb heat rather than holding it in the room. Measure length, width and height, multiply the three, and divide by 45.

A 6 by 6 by 7 foot room is 252 cubic feet, which is 5.6 kW, so the nearest size sold is 6 kW. The heater sizing calculator works out your exact dimensions and carries the full reference table of common room sizes.

A heater under the calculated figure has to run longer to reach its set temperature and in cold weather may not reach it at all. One over the figure costs more to buy and more to run without changing where it settles. Size for the room you measured.

Step 2. The electrical checklist

Confirm all five of these before you buy anything. A licensed electrician sizes the circuit for the specific heater you choose, and on an older panel the wire run or a service upgrade can cost more than the cabinet.

• A dedicated circuit is available for the heater, not a shared one.
• 240 volt service is available at the panel.
• You know the distance in feet from the panel to the heater location.
• There is open breaker space in the panel.
• A licensed electrician has seen the plan.

A heater runs for hours, which makes it a continuous load, so code sizes both the breaker and the wire at 125 percent of its draw rather than at the draw itself. That gap is where most planning goes wrong. The electrical requirements calculator prints the amps, the breaker and the copper gauge for any heater size at 120, 208 or 240 volts.

Step 3. Indoor or outdoor

Check every line that describes your site, then compare the two columns. Most points in one column is a reasonable tie breaker, though a site constraint usually decides it outright either way.

Every model in the catalog states which placement its maker rates it for, and the category pages split the database that way.

Step 4. The cost worksheet

Five lines, and the first one is the only one most listings mention. Fill each in from a quote, not an estimate.

• Cabinet price
• Electrical work, quoted
• Pad or floor preparation
• Delivery, and whether it is curbside or into the room
• Total of the four

For the first line, the 332 models in this database that carry a price verified at a named seller run from $1,099, at a median of $5,987. The full price breakdown by capacity, type and placement shows where a given size lands.

Running cost is a separate line and a much smaller one: heater power times session length times your electricity rate. The running cost calculator uses your state's current residential rate, and every state worked out already is one click further.

Step 5. Ten questions for the dealer or installer

These are the answers that are almost never on a product listing, and each one changes either the price or what arrives.

1. What is the heater's brand and warranty, separate from the cabin warranty?
2. What wood species and thickness does the cabin use?
3. What is the bench depth?
4. Is a heater guard included?
5. How many pounds of stones are included?
6. Where is the control located, on the heater or wall mounted?
7. Is the heater UL or ETL listed?
8. What is the lead time from order to delivery?
9. Is delivery curbside or full service into the room?
10. Is assembly service included, and if not, what does it cost?

Step 6. Compare the models that fit

With a heater size, a placement and a budget, the shortlist is a filter away. The comparison table holds every model with its verified price and specifications, the brand pages put one manufacturer's whole range side by side, and the weekly price drops show what moved this week.

This worksheet is a planning aid, not an electrical or construction specification. A licensed electrician and your installer should confirm the details for your specific site.

The fillable version

Everything above, as a PDF with real form fields: type your measurements and quotes straight into it, tick the checklists, and the totals add themselves up in Adobe. It prints cleanly if you would rather fill it in by hand or hand it to a contractor. It is free, and the form below sends it.