Sleep Cycle Calculator
Find the best times to wake up or fall asleep based on 90-minute sleep cycles.
Recommended (6 cycles ≈ 9 h)
21:15
Breakdown
- Your plan
- Wake at 06:30
- 5 cycles ≈ 7.5 h
- 22:45
- 4 cycles ≈ 6 h
- 00:15
Last updated:
FAQ
Why 90-minute cycles?
A full sleep cycle — from light through deep to REM — lasts roughly 90 minutes, and waking between cycles feels easiest.
Why the 15-minute buffer?
Most adults take 10–20 minutes to fall asleep; the buffer targets when your head hits the pillow.
Do cycles work for everyone?
Cycle length varies from about 80 to 110 minutes by person and age — treat the output as a guide, not a guarantee.
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