Sleep Calculator
Enter the time you want to wake up and see suggested bedtimes that fit complete 90-minute sleep cycles, allowing 14 minutes to fall asleep. Waking at the end of a cycle tends to feel less groggy than mid-cycle. Informational only.
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💡 Good to know: Sleep runs in ~90-minute cycles; waking at the end of one rather than mid-cycle is why timing can matter as much as total hours.
Worked example
6 cycles: 21:16 · 5 cycles: 22:46 · 4 cycles: 00:16
Inputs
- Wake time
06:30
Frequently asked
Why 90-minute cycles?
A full sleep cycle averages around 90 minutes; the tool counts back 6, 5 and 4 cycles from your wake time.
What's the 14 minutes for?
It's an allowance for the time it typically takes to fall asleep after your head hits the pillow.