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Sleep cycles: how many you need and how long they last

One cycle — light sleep, deep sleep, REM — runs about 90 minutes, anywhere from 70 to 120. Most adults get four to six a night. Pick a number of cycles to see the hours, the bedtimes, and what you give up with fewer.

Updated October 3, 2026 · NINDS · NHLBI · AASM

How long one sleep cycle lasts
60 min70 min90 min120 min130 minaverage ≈ 90 min

Range 70–120 min from AASM sleep education; 90-minute average from NINDS

1 h 30 min1 cycle · below the adult range3 h2 cycles · below the adult range4 h 30 min3 cycles · below the adult range6 h4 cycles · below the adult range7 h 30 min5 cycles · inside the adult range9 h6 cycles · inside the adult range10 h 30 min7 cycles · above the adult range12 h8 cycles · above the adult range

Read more

The 90-minute sleep cycle: rule or myth? · Bedtime for your alarm

Sources

  1. Brain Basics: Understanding Sleep — National Institute of Neurological Disorders and Stroke (NIH)
  2. How Sleep Works - Sleep Phases and Stages — National Heart, Lung, and Blood Institute (NIH)
  3. Sleep cycles - Sleep Education — American Academy of Sleep Medicine
  4. Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the AASM and Sleep Research Society — Sleep 38(6):843-844, 2015

General information from population studies (NIH, CDC, NSF, AASM). It is not medical advice and does not replace a clinician who knows you.