How much sleep do we need? We are all different. A baby needs 16 hours of sleep every day. Children 6 to 12 years old need an average of 10 to 12 hours of sleep. Teenagers need 9 to 10 hours of sleep. An adult needs an average of 7 to 8 hours a night. There are some people who need only 3 hours of sleep. Others need 10 hours of sleep. After the age of 50,the average sleep time goes down to 6.5 hours a night. We need less sleep as we get older.