Sleep Calculator

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Most people need 10 to 20 minutes to drift off. This is added to the cycle time.
min
A full cycle is about 90 minutes but ranges from 70 to 120 minutes. Change it if you know yours.
min
Used only to flag whether the recommended option falls in your age range.
5 cycles (recommended)
11:15 PM · 7h 30m sleep
6 cycles9:45 PM · 9h sleep
4 cycles12:45 AM · 6h sleep
3 cycles2:15 AM · 4h 30m sleep
2 cycles3:45 AM · 3h sleep
Recommended sleep for your age7 to 9 hours
Sleep at 5 cycles7.5h
7.5 h
Too little<5Short5-6Recommended6-9Long9+

To wake refreshed, go to bed at 11:15 PM (5 cycles) or 9:45 PM (6 cycles).

  • Each suggested time is a whole number of sleep cycles, so you wake between cycles rather than mid-cycle.
  • A 15-minute buffer to fall asleep is built into every time.
  • The recommended 5-cycle option gives 7.5 hours, which is inside the 7 to 9 hours suggested for a adult (18-60).
  • Cycle length varies by person and night, so treat these as helpful targets, not exact alarms.

Next stepPick the option that gives you 7.5 to 9 hours and keep your sleep and wake times consistent, even on weekends.

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