Wake up refreshed at 4:21 AM

Plan your bedtime to wake up at 4:21 AM. This sleep calculator uses 90-minute sleep cycles and takes 15 minutes to fall asleep into account. Adults: 7-9 hrs, Teenagers: 8-10 hrs, Children: 9-11 hrs, Elderly: 7-8 hrs.

  • 6 cycles
    7:06 PM
    9 hrs
  • 5 cycles
    8:36 PM
    7.5 hrs
  • 4 cycles
    10:06 PM
    6 hrs
  • 3 cycles
    11:36 PM
    4.5 hrs
  • 2 cycles
    1:06 AM
    3 hrs
  • 1 cycles
    2:36 AM
    1.5 hrs
Suggested bedtimes (arrive in bed earlier to allow 15 minutes to fall asleep).
Tip: Sleep cycles average ~90 minutes. Aim for 4–6 full cycles (6–9 hrs).