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Both calculators run independently — change the inputs on either side to compare results.

Sleep Cycle Calculator

Find the ideal bedtime or wake-up time by aligning with 90-minute sleep cycles. Use it when planning your schedule to wake up refreshed, not mid-cycle groggy.

Number of Sleep Cycles

Time to Fall Asleep (minutes)

Fill in the required fields to see your result.

Sleep

Sleep Cycle Calculator

Find your ideal bedtime by working backward from your wake-up time in complete 90-minute sleep cycles. Waking at the end of a cycle (rather than mid-cycle) leaves you feeling more refreshed than the same total hours timed less carefully.

Desired Wake Time (hours (24h format))

Number of Sleep Cycles (cycles)

Fill in the required fields to see your result.

Key differences

	Sleep Cycle Calculator	Sleep Cycle Calculator
Category	Sleep	Sleep
Inputs required	2	2
Result	Total Sleep Time Needed (hours)	Optimal Bedtime (hours)
What it does	Find the ideal bedtime or wake-up time by aligning with 90-minute sleep cycles. Use it when planning your schedule to wake up refreshed, not mid-cycle groggy.	Find your ideal bedtime by working backward from your wake-up time in complete 90-minute sleep cycles. Waking at the end of a cycle (rather than mid-cycle) leaves you feeling more refreshed than the same total hours timed less carefully.