When do babies sleep through the night?

Somewhere between 4 and 6 months, many babies start managing a 6 to 8 hour stretch at night. That is the honest headline, and every word of it is doing work: many, not all, 6 to 8 hours, not 12, and start, because the skill comes and goes for months afterwards.

If you arrived at this page at 3am: nothing is wrong with your baby, and nothing is wrong with your parenting. The ranges below are consistent with HSE and NHS guidance and with what sleep researchers actually measure, which is far messier than the internet suggests.

What does sleeping through actually mean?

In research, sleeping through usually means a stretch of about 6 to 8 hours, often midnight to 5am. It does not mean 12 unbroken hours, and it never means no wakes at all: every baby, like every adult, surfaces briefly between sleep cycles. A baby cycle is around 40 to 50 minutes.

The skill that develops over the first year is not waking less. It is resettling without help: surfacing, checking nothing has changed and sliding back down. When someone tells you their 10 week old sleeps through, they usually mean the baby resettles quietly and the parents never hear about the wakes. Keep that translation in mind before comparing notes at the baby group.

When do babies sleep through the night by age?

• 0 to 3 months: waking every 2 to 4 hours to feed is the design, not a fault. Day and night are mixed up at first, and the longest stretch often lands in the early night. Our newborn sleep guide covers this stage properly.
• 3 to 4 months: one longer stretch of 5 or 6 hours appears for some babies. Then the 4-month regression reorganises sleep into adult-style cycles and often hands some of it back.
• 4 to 6 months: the first genuine 6 to 8 hour stretches commonly arrive here. Commonly, not universally.
• 6 to 12 months: many babies do it most nights. And in study after study, roughly a quarter to a half of babies this age still wake regularly. A 9 month old who wakes once a night has plenty of company.
• After 12 months: mostly settled, with wobbles for teeth, colds, travel and developmental leaps. The wobbles are visits, not relapses.

The baby who slept through from 8 weeks exists, and their parents did not unlock anything you missed. They got a temperament.

When do babies sleep through without a feed?

Separately from the sleeping question, because a baby can sleep beautifully around one honest night feed. Some formula-fed babies drop night feeds around 4 to 6 months. Many breastfed babies feed at night for longer, partly because breast milk digests faster, and that is biology, not a rod for your own back. A baby who still takes a night feed at 8 or 10 months is common and normal.

There is no deadline. If the baby is growing well and the days are fine, you drop the feed when the baby lets it go or when it stops working for your family, whichever comes first. If you are unsure whether a wake is hunger or habit, watch what happens at the breast or bottle: a baby who feeds hard and settles was hungry, a baby who snacks for 90 seconds and dozes was after the comfort. Both are real needs, but only one needs milk, and the feeding frequency guide shows how the feeds themselves space out underneath all this.

Why is my baby fighting sleep?

Nine times out of ten it is timing, in one of two directions:

• Overtired: the wake window ran too long, stress hormones kicked in and the baby is now wired, arch-backed and furious at the thing they need most. Overtired babies also wake more at night and earlier in the morning, which is the cruellest trick in baby sleep.
• Undertired: the window was too short or the last nap ran long, and the tank is simply not empty. The protest is less frantic, more chatty and gymnastic.

Matching the wake window for their age fixes more bedtime battles than any settling technique. After timing come the others: an overstimulating run-up to bed, teething, a cold brewing and, from about 8 months, separation anxiety, where the protest is not about sleep at all, it is about you leaving.

Why won't my baby sleep unless held?

Because your chest is warm, gently moving, smells like milk and safety and has a heartbeat, and the cot has none of those features. Wanting to sleep on a parent is not a disorder or a bad habit you have created. It is what the species does.

Contact naps are fine, and no, you are not ruining future sleep by allowing them. If you want more cot sleep, build it gradually: one well-timed cot nap a day, usually the first morning nap, put down drowsy, hand on chest, and keep expectations low for a fortnight. The rest can stay on you while you both learn. If you might doze off while holding the baby, do it set up safely, and never on a sofa: the safe sleep guide covers exactly this.

Why won't my newborn settle at night?

The first six weeks have their own physics. Day and night are reversed for a while because the body clock has not come online. Evenings bring cluster feeding, where the baby feeds on and off for hours, which is normal fuelling, not failed settling. And the so-called witching hour, that unexplained fussy stretch from roughly 5pm to midnight, peaks around 6 weeks and then fades.

Survive it in shifts if you can: one parent on duty while the other sleeps somewhere else with earplugs, then swap. Our guide to shift sleeping for parents is the practical playbook, and the newborn sleep guide explains what is developmentally on offer this early, which is honestly not much.

What actually helps a baby sleep through?

No secrets, just compounding basics:

• Right wake windows for their age, so bedtime lands on a tired baby instead of a wired one.
• The same wind-down every night: feed, bath or wash, sleeping bag, same song, cot. The sequence itself becomes the sleep cue.
• Dark room, boring nights. Night feeds and resettles happen in dim light with minimal chat, so waking earns nothing interesting.
• Full feeds in the day. A baby distracted into snacking all day often comes back for the calories at night. The feeding enough guide helps you check the days.
• Put down drowsy but awake when it works, so the cot is where sleep starts, not a surprise location discovered mid-cycle. When it does not work, no drama, try again another nap.
• Hold steady through the regressions. The 4-month reorganisation, the 8 month separation anxiety wave and every tooth will each hand you a bad fortnight. They pass faster when the routine does not lurch.

And always on the back, in a clear cot, whatever the hour and however tired you are. The safe sleep rules do not bend at 4am.

When should I talk to the PHN or GP about night waking?

Most night waking is normal development, but bring it to the PHN or GP if:

• The baby snores, breathes with effort or pauses in their sleep.
• Waking comes with signs of pain: screaming that will not settle, back arching with feeds or a baby who seems unwell. Our colic and reflux guide covers the feeding-related versions.
• Feeding is falling off, wet nappies are dropping or weight is sliding across centiles.
• You are at the end of your rope. Parental sleep deprivation is a genuine health issue, it feeds low mood and it is exactly the kind of thing the PHN wants to hear about early. Asking for help with sleep is not an admission of anything except being human.

How do I know if the nights are actually getting better?

At 3am every night feels identical, and memory is the first casualty of sleep deprivation, so progress is invisible from inside it. The fix is a record. Lullagram logs each wake and feed one-handed in the dark, and the week view shows the thing you cannot feel: the longest stretch creeping from 3 hours to 4 to 6 over a month, the wakes drifting later, the pattern behind the chaos. Its Sleep Window learns your baby's own rhythm and predicts the next nap, so the put-down lands in the window instead of past it. It is free to try on Android, iPhone and web.

Every baby has their own timetable. This is a guide, not medical advice. If you are worried, ask your PHN or GP.