Sleep Calculator
Human sleep runs in ~90-minute cycles. Waking at the end of a cycle feels more refreshed than mid-cycle.
Go to bed at one of these times
- 9:45 PM6 cycles · 9 hours of sleep
- 11:15 PM5 cycles · 7.5 hours of sleep
- 12:45 AM4 cycles · 6 hours of sleep
- 2:15 AM3 cycles · 4.5 hours of sleep
Assumes ~15 minutes to fall asleep.