Around 90-110 minutes for adults and in children it's about 45 minutes.
90
you should get on average 8 hours of sleep if you are a growing teenager.
11 years in average.
28 days
Sleep cycles generally last about 90 minutes, however, that is an approximation of the average length of the normal sleep cycle. Actual individuals can have wide variations in the lengths of the cycle. See the attached link for more information.
Average 7-8 hrs
REM
Average 7-8 hrs
4 years we all die
Average of about 7 years
Sleep apnea is a serious sleep disorder that occurs when a person's cycle of breathing is interrupted during sleep. Untreated sleep apnea can disrupt the sleep cycle hundreds of times a night.
The sleep cycle means how human sleeps and at what time. For example if everyday I wake up at 7 in the morning, then take a nap at 12 at noon and go to sleep at 11 at night that is called sleep cycle.