Sleeping time for adults needs to be determined by different age groups and body types, and cannot be generalized. For adults aged 18-64, it is best to sleep between 7-9 hours a day. However, due to the different physique, only 6 hours of sleep or 10 hours of sleep per day are possible, the specific time varies from person to person. For adults over 65 years old, it is generally recommended to sleep about 7-8 hours a day, but there are some older people who get up earlier in the morning and probably sleep only about 5 hours a day. How long you should sleep depends on your state after sleeping. If you only sleep 5 hours a day, and still get up the next day, it means that the body can sleep 5 hours. However, some people sleep 10 hours a day and still get up the next day, which means that 10 hours of sleep may still be insufficient. In addition, adults should pay attention to sleep to ensure regularity, avoid staying up late and ensure regular sleep.