Sleep Calculator

Find optimal sleep or wake times based on 90-minute sleep cycles.

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Time

Fall Asleep Time (minutes)

Best Times to Wake Up

Best Times to Sleep

About Sleep Cycles

Each sleep cycle lasts approximately 90 minutes. Waking up at the end of a cycle (rather than in the middle) helps you feel more refreshed. Most adults need 4-6 complete cycles per night (6-9 hours).