buncha.tools
buncha/time & productivity/sleepcycle

Sleep Cycle Calculator

Sleep happens in 90-minute cycles. Waking at the end of a cycle leaves you feeling rested. Adults typically need 5–6 cycles per night.
Wake time
Time to fall asleep15 min
You should go to bed at
9:45 PM
9h sleep · 6 cycles
Recommended
11:15 PM
7h 30m sleep · 5 cycles
Recommended
12:45 AM
6h sleep · 4 cycles
2:15 AM
4h 30m sleep · 3 cycles
Adults: 5–6 cycles ideal. Teens: 5–6 cycles. Less than 4 cycles regularly may impact health.

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About Sleep Cycle Calculator

Calculate the best time to wake up or go to bed based on 90-minute sleep cycles.

Like every tool on Buncha, this one runs entirely in your browser. There's no upload, no log, no record of what you've pasted or generated. Close the tab and the data is gone.

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