Sleep Calculator

Find the best times to wake up or go to sleep based on sleep cycles for optimal rest.

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Result

Fill in the fields above, then press Calculate.

A sleep calculator recommends optimal bedtime or wake time based on 90-minute sleep cycles to help you wake feeling refreshed.

Select whether you know your wake-up time or bedtime. Enter the time and how long it takes you to fall asleep. The calculator suggests optimal times based on 90-minute sleep cycles.

Examples

Wake up at 7:00 AM

With 14 min to fall asleep: 6 cycles = bed at 9:16 PM (9h sleep), 5 cycles = bed at 10:46 PM (7.5h sleep), 4 cycles = bed at 12:16 AM (6h sleep).

Go to bed at 11:00 PM

With 14 min to fall asleep: 6 cycles = wake at 8:14 AM, 5 cycles = wake at 6:44 AM, 4 cycles = wake at 5:14 AM.

Frequently Asked Questions

Why 90-minute cycles?
Sleep cycles through stages: light sleep, deep sleep, and REM sleep. A complete cycle takes about 90 minutes on average, though it can vary from 80-120 minutes between individuals.
How many cycles do I need?
Most adults need 5-6 cycles (7.5-9 hours). 4 cycles (6 hours) is the minimum for functioning, while 3 cycles (4.5 hours) is sleep-deprived. Individual needs vary.
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Quick Tips

  • •Most adults need 5-6 complete sleep cycles (7.5-9 hours) per night.
  • •Waking at the end of a cycle (light sleep) feels much better than mid-cycle (deep sleep).
  • •Maintain a consistent sleep schedule, even on weekends.
  • •Avoid screens 30-60 minutes before bed for better sleep quality.