How much sleep does a baby need, by age

You want a number. Here are the ranges, which are the honest version of the number - along with the reason the average will only make you feel worse.

4 min read

Sleep need varies enormously between babies of the same age, and it varies within the same baby from week to week. Published guidance describes ranges for exactly this reason, and the range is usually two or three hours wide. A baby at the bottom of it and a baby at the top can both be thriving.

What makes averages actively misleading is that very few babies sit at the average. Told that eight-month-olds sleep thirteen hours, a parent whose baby sleeps eleven and a half concludes something is wrong, when eleven and a half is inside the normal range and describes a great many perfectly well babies.

The ranges, across twenty-four hours

How to tell whether your baby is getting enough

The clock is a weaker signal than the child. A baby getting enough sleep wakes reasonably content, is alert and engaged for most of their awake time, feeds well, and is growing along their own line on the chart. A baby who is short of sleep is irritable, hard to settle, falls asleep at unusual moments, and often - counterintuitively - sleeps worse rather than better.

If your baby is at the bottom of the range and is content, alert and growing, they are probably a low sleep-need baby and there is nothing to fix. If they are inside the range and clearly struggling, look at how the sleep is distributed rather than at the total.

A range is the honest answer. Anyone offering a single number has rounded away the part that matters.

Day and night draw on the same budget

The total is what counts, not the night in isolation. A baby sleeping four hours in the day at ten months is likely to be short at night, whatever else is arranged, because there is only so much sleep available in twenty-four hours.

If you are going to write anything down, write down the whole twenty-four hours for three days. It answers more questions than any other measurement, and it is the one most people have never actually made.

Where the ranges come from

These figures come from consensus statements rather than from any single study - panels of sleep specialists reviewing what is normal across large populations. That is worth knowing, because it explains why they are wide and why they change occasionally as the evidence accumulates.

It also explains what they cannot tell you. A range describes a population, not a prescription for an individual, and there is no evidence that pushing a low sleep-need baby towards the middle of the range benefits them. The numbers are a sanity check for the parent who suspects something is badly wrong, not a target to be hit.

What a low sleep-need baby looks like

Some babies genuinely need less sleep than the middle of the range, and they are frequently mistaken for babies with a sleep problem. The signs are consistent: they sit at the bottom of the range, they are cheerful and alert when awake, they feed well and grow well, and they resist attempts to add more sleep.

The tell is what happens when you try. A baby who is short of sleep responds to an earlier bedtime by sleeping more. A low sleep-need baby responds by lying awake for forty minutes, or by waking earlier the next morning. If that is your experience repeatedly, stop pushing the total up - there is nothing to gain and a difficult bedtime to lose.

When to stop troubleshooting

Consistently sleeping far outside these ranges in either direction, along with irritability, poor weight gain, difficulty rousing, or snoring and noisy breathing, is worth a conversation with your GP or health visitor rather than another schedule change.

General guidance, not medical advice. Your paediatrician's advice takes precedence.