When Do Babies Sleep Through the Night?

The short answer

Many babies become capable of one long unbroken stretch of 6 or more hours somewhere between 4 and 6 months, and a meaningful share sleep through most nights by around 6 to 9 months. But the normal range is genuinely wide, and plenty of healthy, thriving babies still wake at least once well into their second year. There is no single age at which babies are "supposed to" sleep through, and comparing your baby to a friend's is rarely useful.

The reason the answer is a range rather than a date is that "sleeping through the night" depends on three things maturing together: your baby's circadian rhythm, their stomach capacity and feeding needs, and their ability to fall back asleep on their own when they surface between cycles. Those develop on their own timelines, and the last one is the one you can most directly influence.

What "sleeping through" actually means

Here's the part that reframes the whole question. In infant sleep research, "sleeping through the night" typically means an unbroken stretch of about 6 to 8 hours, not the 11 or 12 hours parents usually picture. By that definition, a baby who sleeps from 8 p.m. to 3 a.m. is technically sleeping through, even though no exhausted parent woken at 3 would call it a full night.

This matters because it changes what you're tracking. Instead of waiting for the all-or-nothing milestone of silence from bedtime to sunrise, watch the length of your baby's longest continuous stretch grow over the weeks. A first stretch that lengthens from 3 hours to 5 to 7 is real, meaningful progress, and it's the actual path to full nights, even though it doesn't feel like "sleeping through" yet.

What to expect by age

Newborn (0-3 months)

Sleeping through is not a realistic or even desirable goal yet. Newborns have small stomachs, need frequent feeds day and night, and haven't developed a circadian rhythm, so their sleep is spread in short stretches around the clock. Waking to feed is protective at this stage, and pediatricians generally advise against letting a newborn go too long without feeding, especially before they've regained birth weight.

4 to 6 months

This is when a long consolidated stretch becomes biologically possible for many babies. The circadian rhythm has matured, night sleep is pulling together, and some babies begin sleeping 6 or more hours at a stretch. It's also when the 4-month shift to more adult-like sleep cycles can temporarily increase waking, so progress here is often two steps forward, one step back.

6 to 12 months

A large share of babies are capable of sleeping through most nights in this window, and many do. Those who still wake are usually showing a sleep habit or association rather than a true physical need, which means this is the age where the environment and how a baby falls asleep matter most. Night feeds are still individual and worth discussing with your pediatrician.

Toddler (12 months+)

Most toddlers are physically capable of sleeping through, but night waking still happens, driven by separation anxiety, developmental leaps, illness, or a schedule that has drifted out of sync with their age. Consistency and an age-appropriate wake window carry more weight than they did earlier.

Why babies wake at night in the first place

Every human, baby or adult, surfaces briefly between sleep cycles all night long. Adults roll over and drop straight back down without remembering it. The question is never really "why does my baby wake up," because that surfacing is universal and built in. The question is "why doesn't my baby go back down on their own," and the answers cluster into a handful of causes.

The most common is a sleep association: if your baby falls asleep being fed, rocked, or held, and is then put down asleep, the conditions have changed by the time they naturally rouse at 2 a.m., and they wake fully to ask for those conditions back. Genuine hunger drives waking in younger babies. Beyond that, an over- or under-tired schedule, a room that's too light or noisy, teething, illness, and developmental leaps all push a brief surfacing into a full wake-up.

What actually helps night sleep consolidate

Once a baby is old enough, a few evidence-aligned habits do most of the work.

1. Put your baby down drowsy but awake. This is the highest-leverage change. If falling asleep independently is a skill your baby already has at bedtime, they can use it when they surface overnight, without needing you.
2. Keep the schedule age-appropriate. An overtired baby wakes more, not less. Matching wake windows to age prevents the overtiredness that fragments night sleep.
3. Anchor a consistent bedtime routine. The same short sequence in the same order each night cues sleep and lowers the arousal that keeps babies waking.
4. Get the environment right. A dark room, steady white noise, and a comfortable temperature remove the small disturbances that turn a brief surfacing into a full wake-up.

None of this needs to mean cry-it-out. Our guide to gentle sleep training and to baby sleep as a learned skill walk through how to build independent settling gradually.

Myths that don't help

A few persistent beliefs send tired parents down dead ends. Keeping a baby up later rarely produces a longer night; it usually creates overtiredness and earlier waking. Cereal in a bottle doesn't reliably buy longer sleep and carries real risks. Cutting naps to bank night sleep backfires the same way late bedtimes do. And a baby who slept through once but wakes now isn't broken or regressing permanently, they're almost always in a temporary phase.

When it goes backwards

Sleep is not a one-way street. A baby who was sleeping through and starts waking again is usually in a sleep regression or developmental leap, learning to roll, crawl, or stand, teething, fighting an illness, or simply due for a schedule change as their wake windows lengthen. These setbacks are normal and typically pass within a couple of weeks. The move that helps is holding your responses consistent so a temporary disruption doesn't harden into a new habit, and adjusting the daytime schedule if your baby has outgrown it.

Talk to your pediatrician if night waking is paired with poor weight gain, signs of illness, snoring or noisy breathing, or if a previously good sleeper changes suddenly and doesn't settle back within a couple of weeks.

Key takeaways

• Many babies can sleep a 6+ hour stretch between 4 and 6 months, and many sleep through most nights by 6 to 9 months, but the normal range extends well into the second year.
• "Sleeping through" in research means about a 6 to 8 hour stretch, not a full 12 hours; track your baby's longest stretch growing rather than waiting for total silence.
• All babies surface between sleep cycles; the real question is whether they can resettle independently, which is a learnable skill.
• The biggest levers are being put down drowsy but awake, an age-appropriate schedule, a consistent routine, and a dark, quiet room.
• Going backwards after sleeping through is normal and usually temporary, driven by leaps, teething, illness, or an outgrown schedule.

Sources

1. American Academy of Pediatrics, HealthyChildren.org — guidance on infant sleep and night waking: healthychildren.org
2. Sleep Foundation — research on when babies sleep through the night and night waking: sleepfoundation.org
3. Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) — research on infant sleep development: nichd.nih.gov
4. American Academy of Sleep Medicine — clinical guidance on pediatric sleep: aasm.org
5. Zero to Three — resources on infant sleep and early development: zerotothree.org