What research says about good sleep routines for children
TL;DR
Children 3-5 years need 10-13 hours of sleep. 6-12-year-olds need 9-12 hours. Fixed routines, no screens 1 hour before bedtime, and a dark, cool bedroom are the most evidence-based measures. Good sleep directly affects growth, learning, and behavior.
It’s 9:30 PM and your child is still not asleep. You have sung, told stories, and given the third glass of water. Sleep problems in children are one of the most common challenges for parents of all ages. But it doesn’t have to be an unsolvable problem. Research clearly shows which factors have the greatest impact on children’s sleep quality — and what you can specifically do differently starting tonight. This guide covers it all.
Sleep and children's brains: more than rest
During sleep, growth hormone is released, memory is consolidated, and the brain "cleans" itself of metabolic waste — all of which is critical for children's development.
Sleep is not passive rest. For children, it is an active and critical biological stage. Research from NCBI shows that up to 75% of growth hormone production occurs during deep sleep. Insufficient sleep is directly linked to lower immune function, poorer academic performance, and increased risk of obesity in children.
During REM sleep (dream sleep), the brain consolidates information from the day — a process crucial for learning and memory. Sleep deprivation cuts off this consolidation and gives children a worse start to the next day, no matter how good the activities are.
Behavior is also affected: sleep deprivation is one of the most common causes of impulsivity, concentration problems, and behavioral issues in children — and is often mistaken for ADHD symptoms.
Recommended sleep hours by age
The American Academy of Sleep Medicine (AASM) recommends clear sleep amounts per age group — and many children sleep significantly less than these recommendations.
3-5 years
- 10-13 hours per night
- Including midday nap
- Fixed bedtime 6:30-8:00 PM
- Nap recommended at 4 years
6-12 years
- 9-12 hours per night
- Bedtime 8:00-9:00 PM
- Wake-up routine important
- No screen after 8:30 PM
You can read the full sleep recommendations from the Danish Health Authority. Remember: these numbers are averages — your child may have a personal sleep need that differs slightly from the norm.
Sleep routine elements that work
A consistent evening routine of 30-45 minutes is the most effective single intervention to improve children's sleep and sleep quality.
Research shows that consistent sleep routines reduce the time it takes to fall asleep, improve sleep quality, and reduce night awakenings. A good sleep routine includes:
- Fixed time: The brain's sleep drive is strongest at fixed times
- Wind-down 30-60 minutes before: Calm activities — bath, massage, playing with quiet toys
- Storytelling or reading: Creates emotional security and relaxation
- No screens 1 hour before: Blue light from screens inhibits melatonin production
- Consistency 7 days a week: Weekend sleep times should not deviate more than 30-60 minutes from the weekday routine
What disturbs children's sleep?
Screen light, irregular bedtimes, sugar and caffeine intake, and too warm/bright bedrooms are the most common sleep-disturbing factors for children.
The most documented disturbing factors:
- Blue screen light: Inhibits melatonin for up to 2 hours
- Irregular bedtimes: Confuse the body's circadian rhythm
- Too warm bedroom: Optimal sleep temperature is 16-19°C
- Sugar and juices in the evening: Cause blood glucose fluctuations that disturb sleep
- Stress and worries: Children internalize family stress — calm, predictable evenings help
Bedroom environment: the three most important factors
Dark, cool, and quiet are the three basic principles for an optimal sleep environment — but a child who feels safe and has a routine sleeps well in many contexts.
Darkness: Use blackout curtains, especially in summer and in the Nordic countries, where the light lasts late into the evening. Even dim light can reduce melatonin secretion in children.
Temperature: The bedroom should be kept at 16-19°C. Many families have the bedroom too warm — an easy and free adjustment.
Noise: White noise (fan, sound machine) can help children fall asleep and stay asleep, especially in homes with background noise.
When do sleep problems require professional help?
Most sleep problems in children are resolved with consistent routines. But persistent sleep disturbances may require professional assessment — especially with snoring, breathing stops, or extreme sleep problems.
Contact your doctor if:
- The child snores loudly, has breathing pauses during sleep (signs of sleep apnea)
- The child is persistently tired despite sufficient hours of sleep
- Sleep problems have lasted more than 3-4 weeks despite routine changes
- The child has nightmares or night terrors more than 2-3 times a week
See more about children’s sleep and well-being on our inspiration blog or the Danish Health Authority’s sleep page.
Good sleep is not a luxury — it is the foundation for everything: growth, learning, behavior, and well-being. And it starts with a consistent, calm evening routine that signals to the child's brain: now it’s time to rest.
If you start with just one element — a fixed bedtime — you are already well on your way.
Frequently Asked Questions
How many hours should a 4-year-old child sleep?
The American Academy of Sleep Medicine recommends 10-13 hours of sleep for children aged 3-5, including any naps. Most 4-year-olds sleep best with a bedtime between 7:00 PM and 8:00 PM.
What should I do if my child does not want to sleep?
Establish a consistent, calm evening routine lasting 30-45 minutes. Remove screens 1 hour before bedtime. Keep bedtime fixed, even on weekends. Most children respond positively within 1-2 weeks to a consistent routine.
Is it normal for children to wake up at night?
Yes — everyone partially wakes between sleep cycles. It becomes a problem if the child cannot fall back asleep independently. Teach the child to fall asleep alone at bedtime, and night awakenings typically decrease.
Should preschool-aged children still take naps?
Most children naturally stop taking naps between ages 3-5. Signs that the child is ready to stop napping: it takes more than 1 hour to fall asleep at night, does not sleep at daycare. Follow the child's signals.
Can melatonin supplements help children sleep?
Melatonin can help in some cases but should only be used under medical supervision. It is not a substitute for good sleep routines and a proper bedroom environment. Talk to your doctor before giving your child melatonin supplements.