Sleep Cycle Alarm Calculator

Best bedtimes for your wake time — wake up between 90-minute sleep cycles.

I need to wake at:

How to use

Enter when you must wake up, then click Calculate.

Why 90-minute cycles?

Sleep runs in ~90-minute cycles; waking between cycles avoids grogginess. Five to six cycles (7.5-9h) is ideal.

Should I count falling-asleep time?

Yes — add ~15 minutes to fall asleep. These times already include it.

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