Sleep Calculator
Based on 90-minute sleep cycle science. Choose your mode.
💤 Sleep Science Facts
- One sleep cycle lasts approximately 90 minutes
- A full night = 5-6 complete cycles (7.5-9 hours)
- It takes the average person 14 minutes to fall asleep
- Waking up mid-cycle causes sleep inertia (grogginess)
- Adults need 7-9 hours per night (National Sleep Foundation)