Sleep Calculator

Optimize your sleep cycles to wake up feeling refreshed. Calculate the best time to go to bed or wake up based on 90-minute sleep cycles.

If you go to sleep now, try to wake up at:

Each cycle is approx. 90 minutes. We've added 15 minutes to fall asleep.

10:33 AM

3 Cycles

4.5h of sleep

12:03 PM

4 Cycles

6h of sleep

01:33 PM

5 Cycles

7.5h of sleep

Optimal

03:03 PM

6 Cycles

9h of sleep

Optimal

The 90-Minute Rule

Sleep consists of cycles that last roughly 90 minutes. Waking up at the end of a cycle helps you feel more alert and less groggy.

Consistency is Key

While calculating cycles helps, going to bed and waking up at the same time every day is the best way to improve sleep quality.

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Applications

Optimize your rest by timing your wake-up or bedtimes with natural 90-minute sleep cycles. Ideal for shift workers, students, and anyone looking to reduce morning grogginess.

The 90-Minute Rule

Human sleep is composed of cycles lasting approximately 90 minutes. This calculator accounts for these cycles and adds a 15-minute buffer for falling asleep to help you wake up at the end of a light sleep stage.

Fun Fact: Dolphins sleep with only one half of their brain at a time (unihemispheric sleep), allowing them to stay conscious enough to breathe and watch for predators.

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