TopToolAISleep Time Calculator
Find the best bedtimes to hit a full number of 90-minute sleep cycles before your desired wake-up time, so you wake up between cycles instead of mid-cycle feeling groggy. Working backward from a 6:30am wake-up in 90-minute cycles gives bedtimes of 9:00pm (5 cycles), 10:30pm (4 cycles) or midnight (3 cycles) — falling asleep isn't instant, so the tool builds in roughly 15 minutes to actually drift off.
How to use Sleep Time Calculator
Step-by-step guide to the boxes below. Open it only if you need help.
How to use Sleep Time Calculator
Step-by-step guide to the boxes below. Open it only if you need help.
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1
I want to wake up at Time
Pick the time your alarm needs to go off. The tool counts backwards in 90-minute cycles so you wake up between cycles instead of in the middle of one.
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2
Press “Suggest bedtimes”
Click the button under the boxes. If something is missing or not valid, a short message tells you which box to fix.
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3
Read your result
A list of bedtimes appears, each one lined up with the end of a 90-minute sleep cycle. Change any box and try again to compare different numbers.
Sleep Time Calculator FAQs
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