SLP

Sleep Calculator

Free sleep calculator online. Find bedtime or wake time from 90-minute sleep cycles.

FindWake-up time

6 cycles (9 hrs)

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5 cycles (7.5 hrs)

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4 cycles (6 hrs)

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How to use the sleep calculator free

Calculate Bedtime free with this sleep calculator. It adds about 15 minutes to fall asleep, then counts 90-minute cycles.

How to use the sleep calculator: pick bedtime or wake time, enter the clock time, then read the cycle options.

This sleep calculator free page is built for desktop and mobile. Sleep Cycle Calculator free means no account, no install, and no signup.

How do I use the sleep calculator?

Pick bedtime or wake time, enter the clock time, then read the cycle options. It adds 15 minutes to fall asleep, then counts 90-minute sleep cycles.

How many hours of sleep should I get?

Many adults feel better with 7 to 9 hours. That is usually 5 or 6 complete 90-minute cycles plus time to fall asleep.

Is the sleep calculator free?

Yes. You can calculate bedtime free with no signup and no software to install.

Can I calculate bedtime on mobile?

Yes. This sleep cycle calculator free tool works in a mobile browser. Open the page and get your result.

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