Sleep Cycle & Science

Calculate the best time to wake up based on the 90-minute sleep cycle rule.

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  • Humans sleep in 90-min cycles. Waking up during light sleep makes you feel refreshed.
  • Caffeine has a 6-hour half-life. Avoid it after 3 PM for better sleep quality.
  • Blue light suppresses melatonin. Dim your screens 1 hour before bed.
  • A drop in core body temperature signals sleep. Keep your room around 18-22°C.
  • Includes 15 minutes to fall asleep.