The amount of sleep a child needs varies depending on the child and the child's age.
1-4 weeks old
Newborns usually sleep for 15 to 18 hours per day, but this sleep usually occurs in short periods of two to four hours at a time. The duration of sleep is generally longer for babies who are born premature, while infants who have colic may sleep for shorter periods. This sleep pattern is not associated with the day and night time cycles, as they are yet to develop a circadian rhythm or biological clock.
1-4 months old
A more regulated sleeping pattern emerges by the time the infant is 6-weeks-old. Day and night confusion ends, and the child settles to a more predictable schedule. They may sleep for four to six hours at a stretch, and this generally occurs more often in the evening. They sleep for a total of 14 to 15 hours per day.
4-12 months old
Children up to 11-months-old should ideally sleep for about 15 hours per day, but most of the children only end up getting about 12 hours of sleep. Healthy sleeping habits should be established during this time, as the child becomes more social and develops more or less adult-like sleeping habits. By four-months-old, a child might have three naps, which can reduce to two naps by the time the child is six-months-old. By this time, babies are capable of sleeping through the night. The biological clock matures and regular naps can be established around this time. They usually have a mid-morning nap by 9 a.m., which may last for about an hour. By 2 p.m., the child may go for an afternoon nap that may last for an hour or two. Late afternoon naps may vary in duration and usually begin around 3 p.m. to 5 p.m.
1-3 years old
Children of this age group may sleep for a total of 12 to 14 hours per day. The morning nap may disappear by the time the child moves from 12-months-old to 21-months-old, and the naps will reduce to once a day. Toddlers require up to 14 hours of sleep per day, but they usually manage to get only 10 hours. Children who are between 21-months-old to 36-months-old still need one nap oer day, which may last for one to three hours. Their sleep time varies between 7 p.m. to 9 p.m. in the night to 6 a.m. to 8 a.m. in the morning.
3-6 years old
Children in this age group require a total of 10 to 11 hours of sleep per day. They usually go to bed by 7 p.m. to 9 p.m. and wake up between 6 a.m. to 8 a.m. The nap time reduces considerably by 3-years-old until it completely stops by 5-years-old.
7-12 year old
Children in this age group requires 10 to 11 hours of sleep per day. Most of the children of this age have an average of nine hours of sleep per day. By this age, the sleep time tends to become later, and varying between 7:30 p.m. to 10:00 p.m.
12-18 year old
Sleep is very essential for a teenager. Teenagers need more sleep time than their previous years. However, social pressures commonly prevent them from having the right quantity of sleep time. They should ideally have eight to nine hours of sleep per day.