Sleep Cycle Calculator

Enter your wake-up time and find the perfect bedtime for optimal sleep cycles

How it works: Sleep cycles are roughly 90 minutes long. This calculator shows you what time to go to sleep based on how many complete cycles you want. We add a 15-minute fall-asleep buffer to our recommendations.

What time do you wake up?

Go to sleep by these times:

4 Sleep Cycles (6 hours sleep)

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Bedtime to achieve 4 cycles

5 Sleep Cycles (7.5 hours sleep)

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Bedtime to achieve 5 cycles

6 Sleep Cycles (9 hours sleep)

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Bedtime to achieve 6 cycles

7 Sleep Cycles (10.5 hours sleep)

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Bedtime to achieve 7 cycles

Why Use Sleep Cycles?

A full sleep cycle lasts about 90 minutes. Each cycle takes you through different sleep stages (light, deep, and REM sleep). By timing your sleep to complete cycles, you'll wake up during a lighter sleep stage, making it easier to get out of bed and feel refreshed.

If you wake up during a deep sleep stage, you'll feel groggy and tired. That's why completing full cycles matters more than the total hours.

Recommended sleep amounts: Kids 8-9 hours, teens 8-10 hours, adults 7-9 hours, seniors 7-8 hours.