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Sleep Calculator

Find the best time to wake up or go to bed based on 90-minute sleep cycles, so you wake up between cycles feeling refreshed.

What do you want to do?
Right now: 9:34 PM
Allowing 15 minutes to fall asleep, you'd be asleep by 9:50 PM.
Recommended wake times
Bedtime: 9:35 PM (+15m to fall asleep)
6:50 AMBest
6 cycles · 9h 00m of sleep · 9h 15m from now
5:20 AM
5 cycles · 7h 30m of sleep · 7h 45m from now
3:50 AM
4 cycles · 6h 00m of sleep · 6h 15m from now
2:20 AM
3 cycles · 4h 30m of sleep · 4h 45m from now
Why 90 minutes?
One full sleep cycle ≈ 90 min. Waking at the end of a cycle feels easier than mid-cycle.

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