Sauna Heater Size Calculator

Sauna planning

Sizing on raw room volume is the most common way to end up with an underpowered sauna. Glass, tile and stone soak up heat, so they have to be counted as extra volume. Enter your room below and this works out the adjusted cubic feet to size against, then shows every model we carry that fits — 128 heaters and stoves across six brands.

Room

Width feet

Depth feet

Ceiling height feet

Uninsulated surfaces

Glass, tile, concrete or stone square feet — counts as 45 cu ft each

Exposed log or heavy timber wall square feet — counts as 15 cu ft each

A standard full-glass sauna door is about 12 sq ft. A glass wall panel of 3 × 6 ft is 18. Measure the glass, not the frame.

Filter

Controls apply to electric heaters only. Wood-burning stoves have none, so they are not filtered out by that row.

Raw volume

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Adjusted cubic feet

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Models that fit

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Adjusted cubic feet is the figure sauna heaters are sized against: room volume, plus 45 cu ft for every square foot of glass, tile, concrete or stone, plus 15 cu ft for every square foot of exposed log wall. That adjustment is Harvia's published method and is applied here across all brands as a common standard, so a heater that fits on this page will not be undersized. Always confirm against the installation manual for the model you choose. Wood-burning stoves additionally need a listed, code-compliant chimney.