The amount of sleep a person needs depends on many factors, including age. For example, in general:
- Infants require about 16 hours a day
- Teenagers need about 9 hours on average
- Most adults need 7 to 8 hours a night for the best amount of sleep, although some people may need as few as 5 hours or as many as 10 hours of sleep each day
- Women in the first 3 months of pregnancy often need several more hours of sleep than usual
However, experts say that if you feel drowsy during the day, even during boring activities, you haven’t had enough sleep.
via Sleep Deprivation Effects and How Much Sleep We Need: Babies, Teens, and Adults.