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- Breathing Timer30 × 5-5Five seconds in and five out, thirty times: six breaths a minute, the pace slow breathing research uses, for five minutes.Frontiers in Psychology
- Box Breathing Timer19 × 4-4-4-4LoadedFour counts in, held, out and held, nineteen times over: the five minutes Mark Divine asks for at the least.TIME magazine
- 4-7-8 Breathing Timer4 × 4-7-8In for four, held for seven, out for eight, four times: the most Dr Weil advises at one sitting in the first month.DrWeil.com
What box breathing is, and how to pick your count
Box breathing is Mark Divine’s practice. The former Navy SEAL wrote in TIME in 2016 that he developed it to keep training his breath after the SEALs. His box starts empty: breathe out fully and hold for a count of 4, breathe in through your nose for 4, hold for 4, breathe out through your nose for 4. He asks for at least five minutes of it.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
A count is not a second. A 2023 Stanford trial set each person’s count with a short test: take 4 normal breaths, then one deep breath, and time how slowly you can let it all out. Under 20 seconds meant sides of 3 to 4 seconds; 25 to 45 meant 5 to 6; 50 or more meant 8 to 10.
Cell Reports MedicineBalban et al., 2023, Cell Rep Med 4(1):100895, PMID 36630953
Two rules keep it comfortable. Divine asks that you never clamp down while holding, and the trial told people to shorten every side if they had to strain. If you feel faint, stop and breathe normally. A 2025 study of breathing methods starts from the point that box breathing is popular with psychotherapists yet has little empirical support, so this page describes the method and promises nothing more.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016Cell Reports MedicineBalban et al., 2023, Cell Rep Med 4(1):100895, PMID 36630953Applied Psychophysiology and BiofeedbackMarchant et al., 2025, Appl Psychophysiol Biofeedback 50(2):261 to 276, PMID 39864026
The protocol
In, hold, out, hold, 4 seconds each: a 16 second breath, just under 4 a minute. The second per count is ours.
19 breaths take 5 minutes, the least Divine asks for. The lead-in is the full breath out his version opens with.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
Sit in a chair or lie down. Breathe through your nose if you can, and switch to your mouth if you need to.
Cell Reports MedicineBalban et al., 2023, Cell Rep Med 4(1):100895, PMID 36630953
Keep the holds soft: chest open, nothing pushing against a closed throat.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
This timer sounds a rising tone for each breath in, a falling tone for each breath out and a quiet tap for each hold, has a fullscreen key, and keeps the screen awake where the browser allows; it is free and needs no account. Keep this tab in front, because a browser may pause the sound of a tab you cannot see.
Sessions to try
These are our suggestions. Where one follows a published source, that source is cited under it.
- Gentler
3 seconds a side if 4 is a strain. Set all four sides to 3 and Breaths to 26, which runs just over 5 minutes.
Cell Reports MedicineBalban et al., 2023, Cell Rep Med 4(1):100895, PMID 36630953
- Standard
4 seconds a side, 19 breaths: the pattern the timer opens on.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
- Longer sides
5 seconds a side, for anyone whose breath-out test came in at 25 to 45 seconds. 16 breaths run just over 5 minutes.
Cell Reports MedicineBalban et al., 2023, Cell Rep Med 4(1):100895, PMID 36630953
- Daily practice
Divine’s own habit: one session of 10 to 20 minutes a day, plus a few spot drills of a minute or two. For 10 minutes at 4 seconds, set Breaths to 38.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
Common mistakes
Clamping the holds. Divine asks for an open, expansive feeling while you hold, even though no air is moving.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
Straining to keep 4. The Stanford trial told people to shorten every side as soon as they strained.
Cell Reports MedicineBalban et al., 2023, Cell Rep Med 4(1):100895, PMID 36630953
Gulping the breath in. Spread it over the whole count so the lungs are full as the hold starts.
Doing it in the middle of a complex task. Divine says anywhere and any time, as long as you are not doing something highly complex.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
Questions
What is box breathing?
Four equal sides: breathe in, hold, breathe out, hold, usually for a count of 4 each. Mark Divine says he developed it after his years as a Navy SEAL, as his own practice.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016
How long should you do box breathing?
Divine asks for at least 5 minutes and does 10 to 20 minutes a day himself. The Stanford trial used 5 minutes a day for a month.
TIME magazineMark Divine, on box breathing, TIME, 4 May 2016Cell Reports MedicineBalban et al., 2023, Cell Rep Med 4(1):100895, PMID 36630953
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The same four grounds, drawn six ways. Each is solved so that get ready, work, rest and done stay apart, and so the clock stays readable from across a gym. Pick one and the whole page turns with it; this browser remembers the choice.