When Do Babies Start Sleeping Through the Night by Month?
Key takeaways
- "Sleeping through the night" means a 5 to 6 hour stretch, and most babies reach it between 3 and 6 months.
- An AAP study found half of infants sleeping through by 3 to 5 months, with the fastest progress in the first 4 months.
- Sleep regressions at 4, 8 to 10, and 12 months are normal and temporary.
Image Credits: Wikimedia Commons
"Sleeping through the night" is the milestone every exhausted parent waits for. But the phrase is misleading. Nobody sleeps without waking.
Sleep scientists have confirmed with electrodes and video that adults wake briefly many times a night; we just do not remember it. Babies do the same.
What parents really mean is a long, unbroken stretch of sleep that does not need them. Understanding that definition, and the month-by-month timeline behind it, takes the mystery out of the wait.
This article explains when babies start sleeping through the night by month, including what the phrase actually means, a month-by-month table, the sleep regressions that interrupt progress, and safe-sleep guidance.
What "sleeping through the night" actually means
Researchers define sleeping through the night as a stretch of 5 to 6 hours of sleep without parental intervention. That is the bar used by Gwen Dewar, Ph. D.
, at Parenting Science, who notes that studies suggest most babies begin reaching it between 3 and 6 months of age.
The American Academy of Pediatrics published a landmark longitudinal study in 2010 that sharpened the picture. Researchers followed 75 typically developing infants, collecting parent sleep diaries for 6 days each month for 12 months. They tested three definitions: sleeping midnight to 5 a.
m. , sleeping 8 continuous hours, and sleeping 10 p. m.
to 6 a. m. , which they called the most family-congruent measure.
The results: a 50 percent probability of sleeping through by 3 months under the first two definitions, and by 5 months under the family-congruent one. The fastest consolidation happened in the first 4 months of life.
Even then, progress was bumpy. At 12 months, 11 of the 75 infants still had not met the first two criteria.
The honest version: most babies can do a long stretch by 3 to 6 months, some take much longer, and nearly all of them wake briefly between sleep cycles all night long. What develops is the ability to fall back asleep without help.
Month-by-month sleep table
Every baby differs, but the broad pattern is consistent across pediatric sources. Total sleep falls slowly while nighttime stretches grow.
| Age | Total sleep (24h) | Night sleep | Day naps | What is happening |
|---|---|---|---|---|
| Newborn (0-1 mo) | 14-17 hours | 8-9 hours, broken | Naps around the clock | No circadian rhythm; days and nights mixed |
| 2 months | 14-16 hours | 8-10 hours, 2-3 wakings | 4-6 hours | Day-night differentiation begins |
| 3 months | 14-16 hours | Longer stretches begin | 4-5 hours | Rapid consolidation; many reach 5-6 hour stretches |
| 4 months | 12-15 hours | 9-11 hours, 1-2 wakings | 3-4 hours | Sleep cycles mature; regression common |
| 5 months | 12-15 hours | 10-11 hours | 3-4 hours | Half sleep 10 p.m. to 6 a.m. per AAP data |
| 6 months | 12-14 hours | 10-12 hours, 0-1 wakings | 2-3 hours | Many sleep through; solids may begin |
| 9 months | 12-14 hours | 10-12 hours | 2 naps | Separation anxiety can disrupt nights |
| 12 months | 12-14 hours | 10-12 hours | 1-2 naps | Most sleep through; some still wake |
Atlanta pediatrician Jennifer Shu, MD, told WebMD that most babies start sleeping at night at about four months of age. Parents should not expect 10 to 12 unbroken hours yet, she said, but a five-hour stretch followed by another good stretch after a night feeding is realistic.
One caution from the research: early long stretches do not guarantee consistency. Parenting Science notes that babies often sleep through occasionally before doing it regularly. An irregular pattern, with good nights mixed among wakeful ones, is normal for months.
Image Credits: Wikimedia Commons
Sleep regressions that interrupt progress
Just as nights improve, many parents hit a wall. Sleep regressions are periods when a baby who was sleeping well suddenly wakes more. They are developmental, not behavioral, and they pass.
The 4-month regression is the most famous. Around this age, sleep cycles permanently mature from newborn patterns into adult-like cycles with distinct stages.
Babies wake fully between cycles and have not yet learned to connect them. It often lasts 2 to 4 weeks.
The 8 to 10 month regression ties to milestones and separation anxiety. Babies learning to crawl, pull up, or stand practice in the crib at 2 a. m.
Around the same time, they realize parents exist when out of sight and protest the separation. A consistent goodbye ritual and peek-a-boo games during the day help.
Further bumps often arrive around 12 months (walking, first words), 18 months (independence, nightmares beginning), and 2 years (imagination, bedtime resistance). Each follows the same arc: a developmental leap disrupts sleep for a few weeks, then the new normal is better than before.
During a regression, keep the routine boring and consistent. Avoid introducing new sleep crutches you do not want to keep. Most regressions resolve on their own within 2 to 6 weeks.
What helps longer stretches happen
A consistent bedtime routine is the single most recommended step across pediatric sources. Bath, book, song, bed, in the same order at the same time. The routine cues the brain that sleep is coming.
Put the baby down drowsy but awake. This is the classic advice for a reason: babies who fall asleep in the crib learn to return to sleep there when they surface between cycles. Babies who always fall asleep being held or fed often need the same conditions to fall back asleep at 3 a.
m.
Separate day from night early. Keep nights dark, quiet, and boring, and days bright and social.
Do not wake a sleeping baby to feed unless the pediatrician advises it. Save the exciting play for daytime.
Shift calories to daytime as the pediatrician approves. By around 6 months, most babies can go without a night feed, and dropping it often extends the long stretch. Discuss timing with the pediatrician rather than deciding alone, especially for smaller or slower-gaining infants.
Image Credits: Wikimedia Commons
Safe sleep guidance
Longer nights matter, but safe nights matter more. The American Academy of Pediatrics updated its safe-sleep recommendations in 2022, based on 159 studies, and the core advice is clear.
Place babies on their backs for every sleep, on a firm and flat surface. Share the room, not the bed, for at least the first six months.
Room sharing on a separate surface is associated with up to a 50 percent lower risk of SIDS compared with a separate room. Keep soft objects, pillows, blankets, and bumpers out of the sleep area.
The AAP also advises against inclined sleepers, advises offering a pacifier at sleep times, and recommends avoiding overheating. Breastfeeding, when possible, is associated with lower sleep-related death risk.
This is general information about widely published guidelines, not medical advice for any particular child. Questions about a baby's sleep, feeding, or development belong with the family's pediatrician.
Frequently asked questions
Is it normal for a 5-month-old not to sleep through the night?
Yes. The AAP study found only about half of infants sleeping through by 5 months on the strictest measure. A wide range of normal extends well beyond 6 months.
Do sleep regressions mean something is wrong?
No. Regressions at 4, 8 to 10, 12, and 18 months line up with brain development and milestones. They typically resolve in 2 to 6 weeks with a consistent routine.
Should I sleep train to get longer nights?
That is a family decision to discuss with the pediatrician. Methods range from gradual fading to graduated check-ins. What the evidence supports is consistency: whatever approach the family chooses works better when applied the same way every night.
When can babies drop the night feeding?
Many babies are ready around 6 months, when growth has slowed and daytime calories suffice. The pediatrician should confirm, especially for preterm or slower-gaining infants.
Outlook
Most babies reach a 5 to 6 hour nighttime stretch between 3 and 6 months, with the steepest progress in the first 4 months. Regressions will interrupt the trend, and that is normal development doing its job. Keep the routine consistent, keep the sleep space safe, and give new patterns a few weeks before judging them.
If a baby's sleep seems severely disrupted, if breathing looks labored, or if growth or development raises concerns, talk to the pediatrician. This article covers general patterns from published research; it is not medical advice, and every baby's timeline is their own.
---
About the author: Rive News is the research desk behind these explainers, covering practical questions with verified facts and named sources.
Related stories
- How Many Liters Backpack for a 2-Week Carry-On Trip
- Why Does Bread Go Stale Faster in the Refrigerator?
- Why Do Knees Hurt When Squatting but Not Running?
- Why Does My Dog Stare at Me While I Eat?
Subscribe for one practical explainer like this in your inbox every morning.
Rive News follows a corrections policy: factual errors are fixed promptly and noted with an update timestamp.
Related stories
Why babies cry more in the evening: the witching hour explained
The witching hour is the fussy evening stretch most newborns hit daily. Why overtiredness, cluster feeding, and overstimulation stack up
Why Your Baby Wakes Up the Second You Put Them Down
Newborns wake when put down as the startle reflex, light sleep, and lost warmth hit at once. It is normal and peaks early, fading
How to handle toddler tantrums without yelling
Tantrums peak between 18 and 36 months as the brain learns self-control. Co-regulation works: stay calm, name the feeling, hold