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BOLT score calculator

Your BOLT score is the control pause: sit down, let a normal breath out, pinch your nose, and time how long it takes until your body first asks for air. The timer below runs that protocol and puts the result in the published bands.

It is not a maximum breath hold. Stop at the first definite urge, not at your limit.

Sit down, breathe normally, then press start

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How to take the measurement

  1. Sit upright and breathe normally through the nose for about a minute.
  2. Take a normal breath in, then a normal breath out. Do not fill your lungs and do not force the air out.
  3. Pinch your nose so no air gets in, and start the timer at the end of that exhale.
  4. Stop at the first definite urge to breathe: the first swallow, throat tightening, or diaphragm twitch.
  5. Release your nose and breathe in through it. If the breath after the hold is a gasp, you pushed too far.

Measure first thing in the morning, once a day at most, in the same position. Test-retest variation in the same person runs around six percent over a month, so a change of a second or two is noise, not progress.

Where the bands come from

The cut-offs on this page are Patrick McKeown's, published in The Oxygen Advantage (William Morrow, 2015) and on oxygenadvantage.com: under 10 seconds, 10 to 20, 20 to 30, and 40 seconds as the target for a healthy adult. He publishes nothing for 30 to 40, so the table above leaves that row labelled as unpublished instead of guessing. Buteyko Clinic publishes a five-band control pause table for the same measurement with different boundaries, and the two disagree between 20 and 25 seconds. Pick one scale and stay on it.

Both of those are vendor sources. The independent evidence is thin and it does not support ranking people by their score: a 2024 study of 49 elite speedskaters found no association between BOLT and any Wingate or cardiopulmonary measure, and its authors state plainly that the test has not been scientifically validated in sport (Kowalski et al., Frontiers in Physiology 2024;15:1430837). What the measurement does well is repeat, so your own trend across weeks is the part worth reading.

How to improve your BOLT score

The score rises with regular, unforced practice, and it falls when you chase it. Everything below is dry-land work.

  • Breathe through the nose, all day. The cheapest change and the one most people skip. Nose breathing at rest, walking, and asleep where you can.
  • Slow paced breathing. Five to ten minutes of long, quiet breathing with no retention. The full breath cycles pacer and box breathing both do this job.
  • CO2 tables, not more tests. Repeated exposure to the urge to breathe is the training. Testing is only the measurement. The CO2 table generator builds the session.
  • Space the sessions. Rest days matter more than extra rounds. The training plan builder places them for you across 4 or 6 weeks.
  • Expect slow movement. McKeown reports roughly 3 to 5 seconds a week in the early range, and less once you are past 20 seconds.

What this is not

BOLT is a breath-hold comfort measure, not a lung test and not a medical screening. A score on this page says nothing about your lung capacity, your lung function, or whether your lungs are healthy. It does not diagnose anything, it is not medical advice, and a low number is not a symptom. If breathing is a problem for you, that is a conversation with a clinician.

Dry land only. Take this sitting down, away from water. Never hold your breath in or beside water without a trained buddy watching you. See the safety guide.

Where to go next

The CO2 baseline test times the same kind of signal from a full breath instead of a normal exhale, and it is the number an equanimity table is sized from. The training plan builder turns a maximum hold into a week-by-week schedule. For the term itself and where its evidence runs out, read CO2 tolerance explained.