Cold Plunge Calc
Cold plunge & ice bath

Stop guessing how long to stay in the cold.

A free training system that checks your risk, calculates a safe plunge time for your water temperature and goal, then builds a week-by-week plan toward the roughly 11 minutes a week that regular cold-water swimmers tend to accumulate.

1 · Quick safety check2 · Your plunge today3 · Your 6-week plan
1

Quick safety check

Cold exposure is not safe for everyone. Tick anything that applies to you — your answers stay on this device and adjust the times we recommend.[1]

No major red flags. Start conservatively and build up — the times below already err on the safe side.

2

Your plunge today

50°F
Experience
Main goal
lbs
Recommended time
0:30to2:00
Safe maximum
3:00
Est. calories
~18
Risk level
Low
  • Have someone nearby, especially in open water.
  • Get out if you feel dizzy, numb beyond the skin, or can't control your breathing.

Why this time?

Cold-water tolerance drops fast as the temperature falls, so colder water means shorter sessions. The range above starts from typical adaptation times for your experience level, then scales for your water temperature and goal. Adaptation builds through regular, repeated exposures rather than one long, miserable session.[2]

Guided session timer

Run your plunge with a steady rhythm: settle your breathing, ease in, hold, then warm back up. We'll offer to log it when you finish.

Hold time2:00

Your weekly dose

Adaptation follows your weekly total, not single heroics. Aim for about 11 minutes a week across your sessions. Everything here stays on your device.

—of 11 min target
This week
Week streak
— weeks on target

Recent sessions

Add a past session

Your shareable plan card

Generate a clean card of your cold plunge plan — download it or share it on X, Reddit, or your group chat.

Cold plunging for a specific goal?

The right time, temperature, and timing change depending on why you're plunging. These guides go deeper on each — each one built on real research, not gym-bro hearsay.

After a workoutRecover fast without blunting your strength gains.For recoveryWhat cold really does for sore muscles.For weight lossBrown fat, calories, and an honest reality check.For sleepIt can help — but timing is everything.For anxiety & stressWhat the evidence supports, and what it doesn't.For inflammationThe counterintuitive truth most people miss.

References

The recommendations on this page draw on the following sources. Always treat them as general information, not personal medical advice.

  1. [1]Harvard Health Publishing. "Research highlights health benefits from cold-water immersions," reviewed by Howard E. LeWine, MD. May 2025.
  2. [2]Søberg S, et al. "Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men." Cell Reports Medicine, 2021.
  3. [3]Dr. Susanna Søberg, interview with ZOE: "After a year following them, we saw that they did 11 minutes of cold water immersion per week, divided on two to three days."