Sleep Cycles
Best bed and wake times based on 90-minute cycles.
24-hour format (e.g. 07:00 or 23:30)
The average person takes 10–15 minutes to fall asleep.
Tip: Sleep alternates in ~90-minute cycles. Waking between cycles prevents morning grogginess.
Suggested Bedtimes
Based on 90-minute sleep cycles; fall asleep at these times to wake refreshed:
21:45 Optimal
23:15 Optimal
00:45 Sufficient
02:15 Minimum
Cycles & Duration Breakdown
| Cycles | Duration | Recommended Scenario |
|---|---|---|
| 6 cycles | 9.0 h | Full recovery, athletes or adolescents |
| 5 cycles | 7.5 h | Optimal baseline for adults, peak focus |
| 4 cycles | 6.0 h | Minimum recommended for healthy adults |
| 3 cycles | 4.5 h | Emergency short rest, avoids deep-sleep inertia |
90-Minute Sleep Hygiene & Science
- Human sleep consists of roughly 90-minute cycles alternating between light sleep, deep sleep, and REM.
- Waking at the end of a cycle feels refreshing; waking in deep sleep causes sleep inertia.
- Falling asleep typically takes 10–15 minutes, pre-factored into calculations.
- Keeping a regular sleep and wake schedule is far more effective than weekend catch-up sleep.