Enter your wake-up time to find the best bedtimes based on 90-minute sleep cycles.
Why Sleep Cycles Matter
A complete sleep cycle lasts about 90 minutes and includes light sleep, deep sleep, and REM (dream) sleep. Waking up at the end of a cycle—rather than in the middle—helps you feel more alert and less groggy.
Most adults need 4-6 complete cycles (6-9 hours) per night for optimal health and energy.