How much sleep does my child need? Hours by age, 4 months to 18

How much sleep does my child need?

The numbers below come from a 2016 consensus statement by the American Academy of Sleep Medicine (AASM). A panel of experts reviewed the research on sleep and health and agreed on the amount kids should get regularly, over every 24 hours. For kids under 6, naps count toward the total. The statement does not cover babies younger than 4 months. The CDC lists the same ranges.

The AASM consensus says that sleeping the recommended number of hours on a regular basis is associated with better health outcomes, and that regularly sleeping fewer hours is associated with attention, behavior and learning problems. Those are associations, not a promise that eight hours fixes everything.

Think of the ranges as a window, not a target. A 9-year-old who wakes up happy on 9 hours is fine. A 9-year-old who needs a wake-up call at 7 and is still a bear at 4 p.m. may need an earlier bedtime even if they technically land in the range.

How do I know if my child isn’t getting enough sleep?

Kids rarely say “I’m tired.” They show it. Short sleep is linked to attention, behavior and learning trouble, so the signs often look like a behavior problem when they are really a sleep problem.

• Hard to wake up on school days and groggy for a long time after.
• Falls asleep in the car, in front of the TV or at school.
• More meltdowns, shorter fuse, big feelings over small things.
• Some kids get silly and wound up when overtired instead of yawning.
• Trouble paying attention, remembering homework or switching tasks.
• Sleeping way later on weekends than on school days, by a couple of hours or more.

Why does my teen stay up late and sleep in?

It is biology, not just attitude. A review of teen sleep by Carskadon and Tarokh describes two changes during puberty. First, the body clock shifts later, so melatonin starts later in the evening. Second, sleep pressure builds up more slowly across the day. That is the sleepy feeling Deno, the adenosine character, piles up while we’re awake. In teens, the pile grows more slowly, so they can stay up longer without feeling it.

What does not change is the need for sleep. The authors say the need for sleep may stay at a similar level in early and late adolescence. So a 15-year-old who is wide awake at 11 p.m. still needs most of nine hours. The review points to a mismatch with school start times: in a National Sleep Foundation poll it cites, school-night sleep fell from about 8.4 hours in sixth grade to about 6.9 in twelfth, while weekend sleep ran an hour or more longer.

What helps is working with the clock instead of fighting it: morning daylight, a firm wake-up time on school days, a phone-off time that leaves room for sleep, and a bedtime you set together rather than announce. A deal tends to land better with a teen than an order does.

Does evening light really change sleep?

In one small in-home study of 36 healthy preschoolers aged 3 to 4.9, an hour of light before bedtime cut melatonin by about 85 percent on average, with a range of 69 to 99 percent, compared with the evening before in very dim light. Even dim light of 5 to 40 lux, far dimmer than a normally lit room, lowered it by about 78 percent on average, and in 62 percent of the kids it was still below half its usual level 50 minutes after the light was switched off.

That is Mela’s story: Mela is the body’s “night is coming” message, and bright light in the evening turns her down. The study measured melatonin, not how well the kids slept afterward, and kids differed from each other. But it explains why lamps low and warm after dinner is such common advice, and why little kids may be extra sensitive.

You do not need a lab. Dim the house after dinner. Skip the overhead lights in the bath-and-book hour. Let the morning be bright instead, since daylight helps set the body clock.

Should phones and TVs be in the bedroom?

The research says no. In a study of 2,048 fourth and seventh graders in Massachusetts, children who slept near a small screen, like a phone or tablet, got about 20 fewer minutes of sleep on weekdays, and were more likely to say they did not feel rested. A TV in the room went with about 18 fewer minutes. This was a one-time survey, so it shows an association, not that the screen caused the shorter sleep.

The AAP’s 2026 media policy points the same way. It says to avoid screens for an hour before bedtime and to keep devices out of bedrooms. That is Bedi’s story: a phone in the bedroom goes with worse sleep even when nobody is using it, because the pings, the temptation and the light are all just an arm’s reach away.

The easy fix is a charging station in the kitchen for every phone in the house, yours included. It stops being a punishment when the rule is for everyone.

Does a regular bedtime matter more than the exact bedtime?

A lot of sleep research points to regularity. In a UK study of 10,230 seven-year-olds, kids whose bedtimes were not regular had more behavior difficulties, rated by both their mothers and their teachers. Kids who moved from irregular to regular bedtimes improved, and the more often bedtimes varied, the worse behavior scores tended to be. The authors cautioned that cause and effect are far from clear in the general population of children.

That is Lati’s story: late bedtimes that change every night confuse the body clock. A good target is the same bedtime every night, give or take an hour, including weekends. A predictable routine of bath, book, lights out matters as much as the number on the clock.

What else gets in the way of sleep?

Caffeine is the quiet one. Cola, iced tea and energy drinks can keep a young body awake for hours, and pediatricians advise against energy drinks for kids. Kafi, our caffeine villain, has a simple rule: none after lunch.

Worries can do it as well. A kid who can’t fall asleep may still have the day running in their head. A short, predictable wind-down and a few quiet minutes of talk at bedtime may help more than a new rule.

What you’ll see at home

• A school-morning wake-up is a fight, and your kid is groggy for an hour.
• Bedtime keeps slipping past the time you set, and weekends run two hours later.
• Your teen is wide awake at 11 p.m. and a zombie at 7 a.m.
• Your kid gets a second wind right when you want them in bed.

Try tonight

1. Charge every phone in the kitchen tonight, yours too, and tell your kid it is a family rule.
2. Lower the lights and the volume one hour before bed, and keep the lamps warm instead of bright.
3. Pick one bedtime and wake time, write them down, and stick to them for the next week.

Questions parents ask

Keep reading

• What does melatonin do? Your kid’s own night signal, explainedMelatonin is the hormone the body makes to say night is coming. How light affects it in kids, why teens run late, and habits that help sleep.
• Do screens before bed lower kids’ melatonin?Bright evening light can push back the body’s own melatonin. See what one preschool study found and how to dim the evening with Glo.
• Should kids sleep with their phone in the bedroom?Phones in kids’ bedrooms are linked to less sleep. Meet Bedi, the villain behind it, see what the research found and how to beat it tonight.
• Do irregular bedtimes affect kids’ behavior?Irregular bedtimes are linked with more behavior struggles in kids. See what a 10,230-child study found and how to keep bedtime steady.
• Is caffeine safe for kids? Energy drinks, cola and iced teaEnergy drinks are not appropriate for kids, and caffeine can push sleep later. Meet Kafi, find hidden caffeine and set a simple house rule.
• Why can’t my child fall asleep at night?Lights out, brain on. Why kids lie awake, how Corti, Gabi and the body clock work, and calm habits to try tonight. Plus when to call the pediatrician.
• Why does my child get a second wind at bedtime?Yawning at 7, bouncing at 9:30. What a bedtime second wind may be, what Mela, light and the body clock have to do with it, and how to catch the window.
• What to say when your child says “I can’t sleep”What to say when your child says “I can’t sleep”: calm, brief lines for 10 p.m., how to handle bedtime worries, and what to leave for morning.
• 13 year old brain: what’s normal at ages 12 to 14?Why early teens grow fast, fall asleep late, chase rewards and go quiet at home, plus how much sleep they need and what helps you stay close.
• AAP screen time guidelines 2026: what the new policy actually saysThe AAP’s 2026 policy replaced its 2016 hour limits with a Family Media Plan and the 5 Cs. Here is what it says, by age, and what to do this week.

Sources

1. American Academy of Sleep Medicine. Recommended sleep durations for pediatric populations (consensus statement), 2016.
2. Centers for Disease Control and Prevention. About sleep.
3. Carskadon & Tarokh, 2014. Developmental changes in sleep biology and potential effects on adolescent behavior and caffeine use. Nutrition Reviews 72(Suppl 1).
4. Falbe et al., 2015. Sleep duration, restfulness, and screens in the sleep environment. Pediatrics 135(2).
5. Kelly, Kelly & Sacker, 2013. Changes in bedtime schedules and behavioral difficulties in 7 year old children. Pediatrics.
6. Hartstein et al., 2022. High sensitivity of melatonin suppression response to evening light in preschool-aged children. Journal of Pineal Research.