Find your optimal bedtime based on 90-minute sleep cycles
The average sleep cycle lasts about 90 minutes. During this time, your body progresses through five stages of sleep: four non-REM stages and one REM stage. Waking up at the end of a complete cycle—rather than in the middle—helps you feel more refreshed and alert.
Our calculator factors in approximately 15 minutes to fall asleep, then provides you with optimal bedtimes for 4, 5, or 6 complete sleep cycles.