Toolzy

Sleep Calculator

Find the best bedtime or wake-up time by sleep cycles.

To wake refreshed, fall asleep at one of these times:

09:45 PM

6 cycles · 9h

11:15 PM

5 cycles · 7.5h

12:45 AM

4 cycles · 6h

Sleep cycles run about 90 minutes. Enter a wake-up or bedtime to find times that let you wake between cycles.

How to use

  1. Choose wake-up or bedtime mode.
  2. Enter your time.
  3. Pick one of the suggested times.

Frequently asked questions

Why 90 minutes?
A full sleep cycle averages about 90 minutes; waking between cycles feels easier.
Why 15 extra minutes?
It allows an average 15 minutes to fall asleep.

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