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Câu hỏi thường gặp
What time should I go to bed if I wake up at 7 AM?
A common cycle-based target is around 9:45 PM or 11:15 PM, depending on whether you aim for 6 or 5 cycles, with 15 minutes to fall asleep.
Why does bedtime matter for sleep quality?
Going to bed at a consistent time aligned with your wake-up target supports circadian rhythm and can reduce morning grogginess.
How to Use the Bedtime Calculator
Find the best times to fall asleep based on 90-minute sleep cycles and your wake-up time.
- Enter the time you need to wake up.
- See several recommended bedtimes.
- Pick one that gives you 5–6 complete cycles.
Sleep Cycle Logic
Bedtime
Each cycle is ~90 minutes; allow ~15 minutes to fall asleep.
Example:
Input: wake 7:00, 5 cycles
Calculation: 7:00 − 450min − 15min
Result: ≈ 11:15 PM
Real-World Use Cases
Waking Refreshed
Wake at the end of a cycle, not mid-cycle.
Shift Work
Plan rest around irregular schedules.
Tips
Tips
- Waking between cycles feels more refreshing than waking mid-cycle.
- Adults generally need 5–6 cycles (7.5–9 hours).