The toolkit

Free cold plunge and sauna tools

Two small, fast tools for the questions everyone asks in the first week: how long should I stay in, and what should my week look like? Both show their math and their sources, and neither needs an account.

Cold plunge time calculator

Enter the water temperature in F or C, your experience (first week, regular, experienced) and your goal (recovery, mood, cold adaptation). The calculator gives a session length in minutes, a weekly cold-minutes target against the 11 minutes a week reference, the warning thresholds for your temperature band, and a stop-if list. The math and every source sit under the result.

Open the cold plunge time calculator

Contrast therapy builder

Pick sauna minutes, cold minutes, rounds and the order, plus sessions a week. The builder lays out one session on a timeline, totals your week against the 57 minutes heat and 11 minutes cold reference, adds a rest and rehydration line, and prints as a one-page routine.

Open the contrast therapy builder

What the tools will not do

They will not tell you a routine is safe for you. They turn published ranges into a plan and put the safety rules next to it. If you have a heart condition, high blood pressure or take medication for it, are pregnant, or have Raynaud's or poor circulation, talk to your doctor before you start.

Coming next

An ice calculator (how much ice drops your tub by how many degrees), a sauna heat-up time estimator and a rewarming checklist are on the list. Join the early-access list below and we will tell you when the PlungeLog app and new tools land.