how much sleep is necessary in a day?
For example, in general: 1  Infants require about 14-15 hours a day. 2  Teenagers need about 8.5-9.5 hours on average. 3  Most adults need 7 to 9 hours a night for the best amount of sleep, although some people may need as few as 6 hours or as many as 10 hours of sleep each day.