Sleep Calculator

Calculate the time you should fall asleep to reach the certain number of sleep cycles.

Enter the time you want to wake up:
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Sleep Calculator calculates what time to fall asleep to reach a certain number of 90-minute sleep cycles.

A good night's sleep should consist of 5-6 cycles.


Time you want to wake up Number of sleep cycles Suggested time of falling asleep
07:00 5 23:15
05:30 6 20:15