Age by age

The NHS puts the range like this: some newborns "may sleep for a total of around 8 hours a day", others "may sleep up to around 18 hours a day", and "either is perfectly normal". There is no day and night pattern yet, because there is not yet a body clock to make one.

Newborns commonly wake around every two hours to feed. UNICEF UK Baby Friendly's leaflet for parents is direct about this: "It is both normal and essential for your baby to feed during the night. Babies grow quickly in the early weeks and months of their lives and have very small stomachs. Therefore, they need to feed around the clock to meet their needs." The NHS agrees: a newborn is highly unlikely to sleep through the night, because they have tiny tummies.

What is happening biologically: the circadian rhythm, the body clock that sorts day from night, only begins developing at around two to four months, and BASIS notes it is "incompletely established until at least twelve months or later". Baby sleep cycles are also about an hour long against roughly 90 minutes in an adult, and babies enter active sleep first rather than deep sleep. Frequent surfacing is built in.

Some babies begin sleeping longer stretches now. BASIS describes it carefully: "By the time babies are 3 months old some (but not all) begin to start settling (sleeping through a night-time feed for a stretch of up to 5 hours). By the time they are 5 months old, half of them may have slept for an eight-hour stretch on some nights."

Read that "on some nights" closely. One long stretch does not become the new normal, and a baby who manages it in March may not in April. BASIS also reports that this consolidation happens in only about one in three babies. Many families notice waking increase around four to five months, which is well documented and normal.

The NHS says some babies at this stage sleep around 15 hours in 24, most of it at night. Others sleep considerably less and are fine.

The most useful figure for this age comes from the Lullaby Trust: around a third of babies will have never slept all night by 12 months. If that is your baby, they are in a very large group.

Waking often increases again around eight to nine months. The NHS says separation anxiety commonly emerges between six months and three years, and many parents find it shows up at night, though the NHS page on it does not itself mention sleep, so that link is an inference rather than a stated fact.

The NHS range is 11 to 14 hours in 24, naps included. Galland's review found a normal range of 0 to 2.5 wakings a night here.

BASIS states it plainly: "Some normal babies therefore continue to wake several times during the night after one year." A toddler who still wakes is not behind. Language, walking and separation are all changing fast, and nights often reflect that.

The NHS says most two year olds need about 12 to 14 hours of sleep, including naps.

We are not giving a figure for how often two and three year olds wake at night, because we could not find a reliable UK source for one. Plenty of websites publish a number anyway. The honest answer is that waking at this age is common, and nobody can tell you exactly how common.

The NHS says most children aged 3 to 5 need about 12 hours of sleep, and that some will still need a nap during the day. Dropping the nap is not a milestone to chase.

Night terrors, which differ from nightmares and usually happen early in the night, peak between the ages of 3 and 8. They look frightening and are generally harmless. There is more on common problems.

The NHS band here is 6 to 12 years, needing 9 to 12 hours. Galland's pooled figure for school-age children was 9.2 hours, range 7.6 to 10.8. The Sleep Charity suggests 10 to 11 hours for ages 7 to 12, with a sensible caveat: "the hours on the chart are a guide and it's more important to focus on sleep quality, not quantity."

Again, we have no verified UK figure for how often children this age wake at night, so we are not publishing one.