How the sleep calculator works
Sleep moves through cycles of about 90 minutes, and waking at the end of a cycle can feel easier than waking in the middle of one. The calculator counts in 90-minute steps and adds about 15 minutes to fall asleep.
Adults are generally advised to get at least 7 hours of sleep a night, which is around 5 cycles. Cycle length varies from person to person, so treat the times as a guide. This tool is for general information and isn't medical advice.
📖 Guide: Sleep Cycles Explained and How Many You Need
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Frequently asked questions
How many sleep cycles do I need?
Most adults do well with 5 to 6 cycles, which is 7.5 to 9 hours.
How long does it take to fall asleep?
The calculator assumes about 15 minutes. If you usually take longer or shorter, adjust the time by that difference.
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