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😴 Sleep Calculator

Find the best wake-up times or bedtimes based on 90-minute sleep cycles to wake up refreshed.

How to Use

  1. Choose whether you want to set a wake-up time or bedtime.
  2. Enter your desired time.
  3. Click Calculate — you will see optimal sleep/wake times based on sleep cycles.
  4. Times highlighted in blue give the most complete sleep cycles.

Frequently Asked Questions

What is a sleep cycle?

A sleep cycle is approximately 90 minutes and includes light sleep, deep sleep, and REM sleep. Waking at the end of a cycle helps you feel more refreshed.

Why 14 minutes to fall asleep?

On average, a healthy adult takes about 14 minutes to fall asleep after lying down. This is factored into the calculation.