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Sleep Calculator

Wake up refreshed — bedtimes and wake times aligned with 90-minute sleep cycles.

Enter a time to see your sleep-cycle options.

Formula

Wake time = bedtime + (5–6 × 90-minute cycles) + ~15 minutes to fall asleep

How to calculate

  1. 1Start from your bedtime and add about 15 minutes to fall asleep.
  2. 2Add 90 minutes per full sleep cycle you want.
  3. 3Five cycles (7.5 hours) or six cycles (9 hours) end in a light stage.
  4. 4To wake at a set time, subtract the cycles and 15 minutes instead.

How to use this calculator

  1. 1Enter the time you need to wake up, or the time you plan to sleep.
  2. 2Choose 5 or 6 cycles for your schedule.
  3. 3See the ideal bedtimes or wake times for each cycle count.
  4. 4Pick the option that fits your evening and stay consistent daily.

Examples

Wake at 6:30

For six cycles, fall asleep by 9:15 pm; for five, 10:45 pm — lights out 15 minutes earlier.

Bed at 11 pm

Waking after five cycles lands near 6:30 am; six cycles lands near 8:00 am.

Common questions

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