Free calculators for your sauna, cold plunge and hot tub

Each tool answers one planning question for your space: your room size and walls, your country's voltage, your electricity price and the weather where you live.

3D Studio
Design it, watch it heat up, find the heater.
Contrast timer
Hot, cold and rest rounds with cues.
Heater size
Which heater kW fits your room, with each maker's own range.
Running cost
kWh and cost per session at your electricity price and climate.
Heat-up time
Minutes to 80 °C for your room, heater and the weather outside.
Electrics
Current, breaker or fuse and cable for your heater: the brief for your electrician.
Sauna size
How many people really fit, and the room size for your group.
Chiller size
Chiller size, pull-down time and daily kWh for your tub and room.
Plunge cost
Chiller versus ice: what holding your plunge cold costs per month.
Hot tub cost
Heat-up time and weekly energy for wood-fired and electric hot tubs.
Ice bath calculator
Kilograms and bags of ice for your bath, from your tap water.
Tub volume & weight
Litres or gallons, weight when full, deck load and filling time.
Build cost calculator
The materials list for your size, priced with your shop's prices.