Are sleep cycles exactly 90 minutes?
No. Cycle length varies, so the times shown are estimates.
Sleep Calculator
Workspace
Schedule
Wake times
Cycle times are estimates.
Sleep needs and cycle timing vary. These times are planning estimates.
References: CDC sleep duration by age and NIH sleep stages.
HelpGuide
How to use
- Choose a wake time or bedtime.
- Compare the suggested sleep schedules.
HelpFAQs
Which age guide should I use?
Choose your adult age group to compare the estimated sleep duration with the displayed guidance.
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