Sleep Cycle Calculator

Enter your wake-up time. We will calculate 5 optimal bedtimes based on 90-minute sleep cycles.

What time do you need to wake up?

Average cycle length (minutes)

Most adults: 90 min. Teens: 80-85 min. Older adults: 95-100 min.

Time to fall asleep (minutes)

Result

History

Input	Result	Date

How It Works

Sleep occurs in cycles of approximately 90 minutes, moving through light sleep, deep sleep, and REM. Waking up at the end of a cycle feels natural and refreshing. This calculator counts backward from your wake time in 90-minute increments.