Baby sleep by age: how much sleep your baby needs, month by month
The honest answer is a range, not a number. Here is what the sleep doctors, the NHS and the Lullaby Trust actually say, age by age.
Updated October 13, 2026 · sources checked October 13, 2026
In short
The American Academy of Sleep Medicine recommends 12 to 16 hours of sleep per 24 hours, naps included, for babies aged 4 to 12 months, and 11 to 14 hours from 1 to 2 years. It sets no figure under 4 months because normal newborn sleep varies too widely; the NHS says newborns often sleep around 18 hours a day, in short stretches.
Sleep hours by age at a glance
Every figure below is a total for 24 hours, naps included. Read the ranges as a guide: the NHS and the Lullaby Trust both stress that babies vary a great deal, and that your baby's pattern is unlikely to match anyone else's.
| Age | AASM recommendation (per 24 h) | What the NHS says | What the Lullaby Trust says |
|---|---|---|---|
| Newborn | No figure: normal variation is too wide | Often around 18 hours, waking to feed | Anywhere from 8 to 18 hours, 2 to 3 hours at a time |
| 3 to 6 months | 12 to 16 hours (from 4 months) | Some sleep 5 to 8 hours or longer at night, not all | Some sleep 8 hours or longer at night, not all |
| 6 to 12 months | 12 to 16 hours | Some sleep around 15 hours, mostly at night | Up to 12 hours at night; teething, illness or hunger can wake them |
| 12 to 24 months | 11 to 14 hours | Around 12 to 15 hours after the first birthday; 12 to 14 hours at 2 | — |
Sources: AASM consensus statement (Paruthi et al., 2016), NHS "Helping your baby to sleep", Lullaby Trust "Baby sleep patterns".
The AASM deliberately gives no target for babies under 4 months. If anyone hands you a precise number of hours for a 3-week-old, it does not come from the sleep medicine consensus.
The newborn weeks: sleep in short pieces
The AAP explains that babies do not have regular sleep cycles until about 4 months of age. Newborns sleep about 16 to 17 hours a day, but often only 1 or 2 hours at a time. The Lullaby Trust adds that a baby's sleep cycle lasts about one hour (an adult's is about 90 minutes), and that babies start each cycle in active sleep, where they wake more easily, for about 20 minutes.
This is why newborn nights feel so broken: your baby is built to surface often, and their small stomach needs frequent feeds. For a realistic picture of a newborn day, see our flexible newborn sleep schedule examples.
3 to 6 months: longer stretches for some
Around this age many babies need fewer night feeds. The NHS and the Lullaby Trust both say that some babies then sleep 5 to 8 hours or more at night, and both add "but not all". The Lullaby Trust notes that by three months the sleep cycle extends to around 90 minutes, and that a simple routine can start to help.
About the "4-month sleep regression"
You will see this phrase everywhere. It is not a term used in the AAP, NHS or Lullaby Trust guidance cited on this page. What these sources do describe:
- the AAP: regular sleep cycles appear at about 4 months;
- the NHS: all babies change their sleep patterns, and growth spurts, teething and illness can all affect sleep;
- the Lullaby Trust: just when you think you have things figured out, the pattern changes again.
So if your 4-month-old suddenly wakes more, you are not imagining it, and you have not done anything wrong. Keep following the safe sleep rules and adjust the routine as your baby grows.
6 to 12 months: nights get longer, waking is still normal
The AASM range is 12 to 16 hours. The AAP notes that it is normal for a 6-month-old to wake during the night and go back to sleep after a few minutes. The Lullaby Trust reports that around a third of babies have never slept all night by their first birthday.
If you are thinking about a structured method, our page on sleep training from 6 months sets out what the trials found, without the hype.
Wake windows: what the evidence says
"Wake windows by age" charts are widely shared online. None of the sources on this page (AASM, AAP, NHS, Lullaby Trust) publishes a wake-window chart. Use them, if you like, as loose ideas, and watch your baby rather than the clock. The AAP's advice for older babies and children is simply to set regular nap and bed times and not to wait until your child is rubbing their eyes.
Habits that help at every age
The NHS and the AAP suggest:
- Make day and night different. Daytime: curtains open, play, normal household noise. Night: low lights, quiet voice, feed and change, then straight back down.
- A short, soothing bedtime routine. Bath, clean nappy, night clothes, a story or lullaby, dim lights, a cuddle.
- From about 4 months, put your baby down drowsy but awake (AAP), so they learn to fall asleep in their own bed.
- Do not rush in at every sound. The AAP says babies need a moment to settle themselves back to sleep.
Never try to make a baby sleep longer or deeper than is usual for their age with products, positioners or extra bedding. The Lullaby Trust warns this can affect a baby's ability to wake if something is wrong.
When to ask for help
- Speak to your pediatrician or health visitor if your baby's sleep worries you, if they seem unusually hard to wake, or if feeding or weight gain is a concern.
- In the UK, call NHS 111 or get an urgent GP appointment if you think your baby might be ill.
- Call 911 (US) or 999 (UK) if your baby stops breathing, will not wake, is struggling to breathe, or turns pale, blue or grey.
As your baby grows into a toddler, the numbers change again: see toddler sleep from 1 to 4 years.
Questions parents ask
How many hours should a 6-month-old sleep?
The AASM range for babies aged 4 to 12 months is 12 to 16 hours per 24 hours, including naps. The NHS notes that some babies aged 6 to 12 months sleep around 15 hours, most of it at night.
Is it normal for my baby to still wake at night at 12 months?
Yes. The Lullaby Trust reports that around a third of babies have never slept all night by 12 months. Waking is common at this age, especially with teething, illness or hunger.
Is the 4-month sleep regression real?
The phrase sleep regression is a popular label, not a term used by the AAP, NHS or Lullaby Trust pages cited here. What they do describe is real: the AAP says regular sleep cycles appear around 4 months, and the NHS says growth spurts, teething and illness all change sleep.
Should I wake a sleepy baby?
The Lullaby Trust says there is no need to wake a baby who sleeps longer, as long as they are feeding, gaining weight and are not unwell. Follow your midwife's or pediatrician's advice if they ask you to wake your baby for feeds.
Sources
- Paruthi S. et al. — Recommended Amount of Sleep for Pediatric Populations, AASM consensus statement (J Clin Sleep Med, 2016) checked October 13, 2026
- NHS — Helping your baby to sleep checked October 13, 2026
- The Lullaby Trust — Baby sleep patterns, how long should my baby sleep? checked October 13, 2026
- HealthyChildren.org (AAP) — Getting your baby to sleep checked October 13, 2026
- NHS — Sudden infant death syndrome (SIDS), including when to call 111 or 999 checked October 13, 2026
Mamavela explains; it does not replace your midwife, doctor or pediatrician, who know your situation. If something worries you, call them. In an emergency, call 911 (US), 999 (UK) or 112.