05:15
4 cycles (6 hours)
Minimum
06:45
5 cycles (7.5 hours)
OK
08:15
6 cycles (9 hours)
Ideal
Each sleep cycle is ~90 minutes. Waking between cycles (not during one) helps you feel refreshed. Allow 15 minutes to fall asleep. Adults need 5-6 cycles (7.5-9 hours).