Saunature

Tools for planning your sauna

Sauna heater size calculator

Enter your sauna’s inside dimensions and glass, stone and log surfaces to find its effective volume and matching heaters sold by Saunature.

Measure your sauna room

Use the finished inside dimensions. Surface areas stay in m² when you change the length unit.

For your consultation only. This does not change the heater calculation or determine seating capacity.

Location
Surfaces that absorb extra heat

Enter the measured area of uninsulated surfaces. Measure a glass door as width × height and include it with glass walls. Count each surface once.

Heaters for your sauna

Enter your dimensions and materials to find matching models.

Outputs and volume ranges shown are for Japan specifications. Other markets use different supplies and specifications; confirm the model for your destination.

Confirm supply capacity, wiring and controller compatibility with your electrician. Single- and three-phase supplies are not interchangeable.

Ask us about heater sizing

Choosing a sauna heater output

Room volume = width × depth × height. HUUM’s sizing guide adds 1 m³ for every m² of uninsulated glass, stone, tile or log wall. For CLIFF and STEEL we use 1.5 m³ per m², following the pre-installation sections of their manuals. Matching uses each model’s own effective volume.

The effective volume range shows the 1× to 1.5× surface allowances. This is an initial estimate. Before selecting a heater, confirm its latest manual, actual insulation and ventilation with us.

HUUM official heater sizing guide

Sources checked: 27 October 2026 (JST)

Calculate sauna ventilation

Still working out dimensions or power supply?

Share your drawing and calculation with us. Saunature can help choose a heater after checking insulation, location and electrical supply.

Ask us about heater sizing