Calculate your optimal bedtime based on when you need to wake up and sleep cycle science. Wake up refreshed during your lightest sleep phase.
The average sleep cycle lasts about 90 minutes and includes all stages of sleep from light to deep to REM. By timing your bedtime to wake up during a light sleep phase, you'll feel more refreshed and alert.
Our calculator works backwards from your desired wake time, accounting for the time it takes you to fall asleep, to find bedtimes that align with complete sleep cycles (4-6 cycles recommended for adults).
Waking up during deep sleep causes "sleep inertia" - that groggy, disoriented feeling. By contrast, waking up during light sleep allows for a smoother transition to consciousness. Most people complete 4-6 sleep cycles per night, depending on how long they sleep.
For adults, 7-9 hours of sleep is recommended, which equals roughly 5-6 complete sleep cycles. Use our calculator to find the perfect bedtime for your schedule!