Sleep Calculator
Calculate optimal sleep and wake times based on 90-minute sleep cycles to wake up refreshed.
When should I wake up?
Enter your planned bedtime to see optimal wake-up times
How It Works
Sleep occurs in cycles of approximately 90 minutes. Each cycle consists of light sleep, deep sleep, and REM sleep. Waking up at the end of a complete cycle helps you feel more refreshed and alert.
- Most adults need 6-9 hours of sleep (4-6 complete cycles)
- It typically takes 15 minutes to fall asleep
- Waking during deep sleep causes grogginess