Baby sleep by age and wakeful phases

0-3 months · 3-6 months · 6-12 months · Sleep · Reviewed 9 June 2026 · All articles

Few things loom larger in early parenthood than sleep. How much should your baby be getting? Why do they keep waking up? Will it ever get easier? The short answers are: quite a lot, because it is developmentally normal, and yes. This guide walks through what to expect at each stage from newborn to twelve months, explains why wakeful phases happen, and covers the safe sleep basics that protect your baby every night.

Why baby sleep is different from adult sleep

Understanding a few basics makes the rest of this guide easier to follow. Babies cycle through sleep stages differently from adults. According to the American Academy of Pediatrics (AAP), newborns spend roughly half their sleep time in REM (active sleep), compared with the small fraction adults experience. In REM sleep, babies breathe irregularly, twitch, and can appear restless. This is normal. Breathing may pause for a few seconds and then resume at a faster rate: the AAP describes this as "normal periodic breathing of infancy" that usually resolves by around six months.

Because babies move through sleep cycles more frequently and spend more time in lighter sleep, they naturally rouse more often than adults. Waking during the night is not a malfunction: the NHS notes that some night waking is to be expected at every age through the first year. The AAP adds an important reframing: a good infant sleeper is not necessarily one who never wakes, but one who is able to settle back to sleep after waking.

Sleep by age: what to expect

Newborns (0 to 3 months): around 16 to 18 hours in fragments

Newborns sleep a great deal, but rarely for long stretches. The NHS states that newborns sleep around 18 hours a day in total, but typically only 1 to 2 hours at a time. The AAP gives a similar figure of 16 to 17 hours per day. The reason for the frequent waking is straightforward: a newborn's stomach is tiny, so they need feeding frequently, day and night, to grow properly.

At this age, babies do not yet have an internal body clock that distinguishes day from night. They have no concept of daytime versus nighttime. The NHS recommends a gentle approach to help them begin learning: during the day, keep the environment bright and engage with your baby normally; at night, keep lights low, voices quiet, and interactions calm and brief. This gradual nudge toward day-night awareness takes weeks, not days.

There is no expectation that a newborn will sleep through the night. Attempting to stretch feeds or ignore night waking at this stage is not appropriate: newborns need those feeds to gain weight and thrive.

3 to 6 months: patterns starting to emerge

Around three to four months, a meaningful shift begins. The AAP notes that babies do not have regular sleep cycles until around four months of age. As those cycles consolidate, you may notice your baby beginning to have more predictable periods of alertness during the day and slightly longer stretches at night. Some babies at this stage may sleep five to eight or more hours at a stretch overnight as they grow and need fewer feeds, according to NHS guidance.

This is also the age at which a simple bedtime routine can start to make a difference. The NHS recommends building a short, consistent sequence: a warm bath, a change into night clothes, a feed, some quiet time, and then placing your baby down to sleep. Doing the same things in the same order each evening helps your baby's brain start to associate those cues with sleep. Keeping the routine calm and the environment dimly lit reinforces the message that night is for sleeping.

Not all babies follow a smooth trajectory at this stage. Some parents encounter what is commonly described as a "four-month sleep regression," a period when a baby who had been settling well suddenly becomes harder to put down and wakes more frequently. This is tied to the maturation of sleep cycles described above: as babies move toward more adult-like sleep architecture, they pass through lighter sleep stages more often and can wake where they previously slept through. It is a sign of normal brain development, not a problem to fix.

6 to 12 months: more night sleep, daytime naps, and more wakeful phases

By six months, many babies are getting around 15 hours of total sleep per day, with the larger share coming at night. The NHS notes that some babies at this age may no longer need a night feed, though many still do, and there is wide variation between babies. By around six months, the AAP observes, it is developmentally normal for a baby to wake during the night and then settle back to sleep on their own after a few minutes.

Daytime sleep at this stage typically organises into two naps: a morning nap and an afternoon nap. Both serve a real purpose. Overtired babies often become harder to settle at night, not easier, so adequate daytime sleep supports better nighttime sleep rather than competing with it.

Wakeful phases continue throughout this period and tend to coincide with developmental leaps. Learning to roll, sit, crawl, pull to standing, and eventually walk all involve significant brain activity. Teething can also disrupt sleep. Illness or a change to routine can knock sleep back temporarily. The NHS advises that growth spurts, teething, and illness all affect sleep patterns and that this is expected. If your baby has been sleeping well and suddenly is not, a cause is usually not hard to identify.

A snapshot: typical sleep totals by age

Age	Approximate total sleep per day	Typical pattern
0 to 3 months	16 to 18 hours	Fragmented, 1 to 2 hours at a time, day and night
3 to 6 months	14 to 16 hours	Longer overnight stretches beginning; 3 to 4 daytime naps reducing to 2
6 to 12 months	Around 15 hours	Majority at night; 2 daytime naps (morning and afternoon)
12 months+	Around 12 to 15 hours	Mostly at night; transitioning toward 1 daytime nap

These figures are approximate. Individual babies vary considerably, and a baby sleeping somewhat more or less than the figures above is not automatically cause for concern.

Helping your baby to sleep: practical guidance

Rest when your baby rests

The NHS is direct about this: try to sleep when your baby sleeps. In the early weeks especially, daytime naps are not a luxury; they are how parents survive on fragmented overnight sleep. Household tasks can wait.

Put your baby down drowsy, not asleep

Once your baby is around four months old, the AAP recommends placing them in their cot when drowsy rather than waiting until they are fully asleep. A baby who falls asleep in their cot learns to fall asleep there. A baby who always falls asleep in arms often needs the same to return to sleep after waking in the night. This one adjustment, though it requires patience at first, supports longer independent sleep over time.

Keep daytime and night different

The NHS recommends keeping curtains open and noise levels normal during the day, and making night feeds and changes calm, quiet, and brief. Avoid overstimulating your baby at night: no play, minimal eye contact, and low or no lights where safe to do so.

A simple bedtime routine helps

The NHS suggests a short, consistent bedtime routine from around three months onward: a bath, a change, a feed, perhaps a quiet song or a short story, and then into the cot. The routine does not need to be elaborate; the consistency is what matters. Aim for roughly the same time each night.

Share the load where possible

The NHS specifically mentions partner support: one parent handling a feed or the early morning wake-up allows the other to get a longer stretch of unbroken sleep. Taking turns is one of the most effective strategies for both parents managing the first months.

Ask for help if you need it

If sleep problems are persistent, your health visitor is the right first port of call. The NHS advises speaking to your health visitor if sleep difficulties continue; they can rule out any underlying issue and suggest approaches suited to your baby's age and temperament.

Safe sleep: the basics that matter every night

Safe sleep guidance exists to reduce the risk of sudden infant death syndrome (SIDS). The NHS sets out clear recommendations that apply from birth.

Always place your baby on their back

Every sleep, for every nap, place your baby on their back with their feet at the foot of the cot (the "feet to foot" position). The AAP also recommends back sleeping for all sleeps until age one. Once a baby can roll both ways independently, you do not need to reposition them if they roll during sleep, but always start them on their back.

Room-share for at least the first 6 months

The NHS recommends that your baby sleeps in the same room as you for every sleep for at least the first six months. Your baby should have their own separate sleep surface: a cot, Moses basket, or bedside crib with a firm, flat mattress. Room-sharing reduces SIDS risk; bed-sharing carries additional risks, particularly if either parent smokes, has consumed alcohol, or has taken sedating medication.

Keep the sleep environment clear

Remove pillows, duvets, cot bumpers, loose blankets, soft toys, and positioners from the sleep space. Use a firm, flat mattress. A lightweight blanket tucked securely under the mattress at chest height, or a baby sleeping bag in the correct tog rating for the room temperature, are both safe options.

Keep the room temperature between 16 and 20 degrees Celsius

The NHS advises keeping the room where your baby sleeps at 16 to 20 degrees Celsius and using a room thermometer to check. A baby who is too warm is at increased SIDS risk. Check your baby's chest or the back of their neck to gauge warmth; cool hands and feet are normal and not a reliable sign of being cold.

Avoid smoking around your baby

The NHS lists exposure to cigarette smoke as a significant SIDS risk factor. Do not smoke near your baby, and do not allow others to do so. This applies both before birth and after.

Breastfeed if you can

The NHS notes that breastfeeding, even partially, is associated with a reduced SIDS risk. This is one of several reasons breastfeeding is recommended alongside the safe sleep guidance above.

When to seek help

Most sleep difficulties in the first year are normal and resolve with time and consistency. Seek care promptly if your baby:

Has pauses in breathing that are prolonged, or turns blue or pale around the lips
Is unusually difficult to wake
Has a fever of 38C or above (or below 36C)
Is not feeding or gaining weight
Seems unwell beyond normal tiredness

If you are unsure, call NHS 111 or contact your GP. Trust your instincts: if something feels wrong, get it checked.

Frequently asked questions

My 8-week-old wakes every 2 hours at night. Is this normal?

Yes. The NHS states that newborns sleep around 18 hours a day but only 1 to 2 hours at a time. Frequent night waking at this age is completely expected. A newborn stomach is small, and regular feeding is necessary for growth. This pattern typically shifts as your baby grows.

My baby was sleeping better and has suddenly started waking more. What is happening?

Wakeful phases are common across the first year and typically coincide with developmental changes: new motor skills, growth spurts, teething, or illness. The NHS notes that all of these affect sleep patterns. These phases usually pass within a week or two. Keeping routines consistent during them helps.

When can I expect my baby to sleep through the night?

The AAP notes that "sleeping through the night" is somewhat misleading: all babies wake during the night as they transition between sleep cycles. What changes over time is the ability to settle back to sleep without needing a parent. Many babies develop this skill gradually between four and nine months. Some take longer, and there is a wide range of normal.

Is it safe for my baby to sleep in a bouncer or car seat?

Inclined and sitting sleep surfaces are not recommended for infant sleep. The NHS advises against prolonged car seat sleeping. Car seats are designed for travel, not sustained sleep: the angle can affect a young baby's airway. Transfer your baby to a firm, flat surface as soon as it is safe to do so.

Should I use a dummy for sleep?

The NHS includes dummy use as a factor associated with reduced SIDS risk. If you offer a dummy for sleep, let your baby take it naturally rather than forcing it, and do not coat it in anything sweet. If the dummy falls out during sleep, you do not need to replace it. Dummy use is a personal choice; the NHS does not mandate it, but notes it is not harmful and may offer some protection.

My baby only falls asleep on me. How do I move them to the cot?

This is very common. The AAP recommends placing your baby in their cot when drowsy but not fully asleep once they are around four months. It often takes a few days of patience for a baby to adjust to a new expectation. Starting with one sleep (often the first nap of the day, when your baby is not overtired) can be easier than starting with bedtime. Your health visitor can suggest age-appropriate approaches if you are struggling.

Keep track of your baby's sleep patterns

Log naps, nighttime stretches, and feeds in one place so you can spot patterns and share them with your health visitor or GP.

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