Sleep Cycle Calculator
Find your optimal bedtime or wake-up time using science-based 90-minute sleep cycles. Wake up feeling refreshed and energized.
Sleep Cycle Calculator
How Sleep Cycles Work
The Science
Your sleep consists of multiple 90-minute cycles. Each cycle includes light sleep, deep sleep, and REM sleep. Waking up at the end of a complete cycle helps you feel more refreshed than waking up in the middle of deep sleep.
Why 90 Minutes?
Research shows that a complete sleep cycle takes approximately 90 minutes. Most adults need 4-6 complete cycles (6-9 hours) for optimal rest. We add 15 minutes to account for the time it takes to fall asleep.