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