7-12 Years Old: 10 - 11 hours per day
At these ages, with social, school, and family activities, bedtimes gradually become later and later, with most 12-years-olds going to bed at about 9 p.m. There is still a wide range of bedtimes, from 7:30 to 10 p.m., as well as total sleep times, from 9 to 12 hours, although the average is only about 9 hours.
12-18 Years Old: 8 - 9 hours per day
Sleep needs remain just as vital to health and well-being for teenagers as when they were younger. It turns out that many teenagers actually may need more sleep than in previous years. Now, however, for many teenagerssocial pressures conspire against getting the proper amount and quality of sleep.