Wake up at 3:45 AM after 7.5 hours of sleep, or 5:15 AM after 9 hours.
These times let you finish whole 90-minute sleep cycles, including 15 minutes to fall asleep.
If you go to bed at 8:00 PM, wake up at one of these times:
Includes 15 minutes to fall asleep. Adults need 7 to 9 hours, so 7.5 hours (5 cycles) is marked as the best fit.
| Wake up at | Sleep | Cycles | |
|---|---|---|---|
| 5:15 AM | 9 hours | 6 | Good for teens and people who need more sleep |
| 3:45 AM | 7.5 hours | 5 | Recommended for most adults |
| 2:15 AM | 6 hours | 4 | Short: below the 7-hour minimum |
| 12:45 AM | 4.5 hours | 3 | Very short: only for an emergency |
| Time to fall asleep | Wake up after 5 cycles | Wake up after 6 cycles |
|---|---|---|
| 5 minutes | 3:35 AM | 5:05 AM |
| 15 minutes | 3:45 AM | 5:15 AM |
| 30 minutes | 4:00 AM | 5:30 AM |
An early bedtime suits children, early risers and anyone with an early start. If you can’t fall asleep this early, it may be too early for your body clock: try moving bedtime later by 15 minutes at a time.
For general information only, not medical advice. If you often feel tired despite enough sleep, snore loudly, or have trouble sleeping most nights, talk to a doctor.