Adults usually have to sleep for a few hours to be scientific.

18-59 years old: 7-8 hours (but the study found that it should not be less than 9 hours).

60-70 years old: 5.5-7 hours (some experts believe that the elderly should also sleep for more than 9 hours)

Optimal sleep calculation formula: let the age be x, and the optimal sleep time y approximately satisfies Y = 2 1-6x 0.3+X/ 10. However, some experts have suggested that the elderly need longer sleep time than adults because of weak qi and blood, so there is y = 22-7x 0.3+x/5.6. In this function, the sleep time of people over 60 years old is increasing.

Extended data

Sleep time refers to a natural physiological phenomenon of human beings and animals. Consciousness is a natural, usually regular pause. During this period, physical strength is restored, eyes can be closed, and the cerebral cortex is at rest.

Sleep time can be divided into intermittent sleep and continuous sleep. Sleep time in general life refers to the total sleep time in a day, that is, the sum of all the time in sleep.

Sleep is a systematic project. In fact, sleeping is not as simple as falling on a pillow, sleeping under a quilt all night, and then waking up when you open your eyes. This is a complicated and gradual process.

References:

Baidu encyclopedia-sleep time