Sleep Calculator
Find the best time to wake up or go to bed based on natural sleep cycles.
Circadian Tip
Melatonin production starts decreasing at the first sight of sunlight. Use blackout curtains for a deeper, uninterrupted slumber.
Sync Your Rhythm
Set your target time to discover the most biologicaly harmonious windows for your rest.
Sleep Calculator
Sleep is not a uniform state but a complex sequence of cycles. Each cycle lasts approximately 90 minutes and transitions through light sleep, deep sleep, and REM (Rapid Eye Movement) stages. Waking up during deep sleep can lead to 'sleep inertia', making you feel groggy regardless of how many hours you've rested.
The Architecture of Sleep
Our bodies cycle through NREM and REM stages. Waking up at the end of a cycle feels natural and leaves you feeling refreshed and alert throughout the day.
Sleep Hygiene
Consistency is the foundation of quality sleep. Try to maintain a regular sleep-wake schedule, even on weekends, to stabilize your internal clock.
90-Minute Cycle Logic
Wake Time = Bedtime + (Cycles × 90 min) + 15 min fall asleepThe calculator works by counting backwards or forwards in 90-minute blocks from your target time, while factoring in the average 15 minutes it takes for a person to actually fall asleep after closing their eyes.
Optimization Scenarios
The 7:00 AM Wakeup
To wake up refreshed at 7 AM, you should ideally go to bed at 11:15 PM (6 cycles) or 12:45 AM (5 cycles).
Midnight Bedtime
If you fall asleep at midnight, your optimal wakeup times are 6:15 AM or 7:45 AM to complete full cycles.