Wake Windows by Age

Awake time grows from about three quarters of an hour at birth to most of the afternoon by the third birthday, and it grows unevenly. A newborn manages roughly 45 to 60 minutes between sleeps; a four-month-old an hour and a half to a bit over two hours; a nine-month-old two and a half to three and a half; a toddler four to five and a half. Those are bands rather than numbers, they overlap, and a baby at either end of one is perfectly ordinary. Your baby is the authority — this is a starting point.

The table below is the whole answer in one place. What follows it is the part the other results leave out: where these bands come from, what they are not, and which months are the ones where the shape of the day genuinely changes.

Wake windows by age, as bands

The wake window calculator reads the same bands off an age slider and, if you tell it when your baby last woke, adds the band to the clock and gives you the earliest and latest the next sleep is likely to be wanted. It never prints one time, for the reason in the next section.

Where these bands come from, and what they are not

No health body publishes a wake-window table. Not the NHS, not the American Academy of Pediatrics, not the NIH. If you have seen a chart of exact minutes by month — and you will have, because every result above this one has one — nobody measured it.

What is published is total sleep. The American Academy of Sleep Medicine's consensus statement, which the AAP endorses, gives 12 to 16 hours per 24 hours including naps for infants aged 4 to 12 months, 11 to 14 hours for one- and two-year-olds, and 10 to 13 hours for three- to five-year-olds. Take that total, subtract a night, divide what is left by the number of naps babies that age usually still take, and awake stretches fall out as a range. That is the arithmetic behind every band in the table, and it is why the bands are wide.

For babies under four months the consensus statement deliberately gives no figure at all, because the normal variation in duration and pattern is too wide to be useful. The NHS puts a newborn's total at around 18 hours and says babies may only sleep one or two hours at a time. So the first four rows of the table are the softest on the page, and they are meant to be read as the roughest of guides.

How to use a band without letting it run your day

Watch your baby first and the clock second. The band tells you roughly when to start paying attention; what she does with her eyes, her hands and her voice tells you the rest. Staring past you, slowing down, rubbing at her face, turning away from a toy she liked a minute ago — those are the signals worth learning, and they arrive at a slightly different point in the band for every baby.

One useful pattern, and it is honestly a rule of thumb rather than a finding: the first window of the morning tends to sit near the short end of the band, and the last stretch before bed near the long end. Nobody cited on this page publishes that. It is what parents and this app both see, and it is worth knowing precisely because it means a single number would be wrong twice a day even if it were right on average.

Three or four days of your own notes will beat this table, which is the entire argument for writing them down. A printed day sheet or a tracker — anything you will actually fill in with one hand — turns a week of guessing into a pattern you can read. The sleep schedule generator does the other half: it stacks the bands into a sample day and shows the windows widening through the afternoon, which is what happens when you add four estimates end to end.

When the window is wrong

Usually nothing dramatic happens, and it is worth saying that plainly, because most of what is written about this is written to worry you.

Too short, and a baby often will not settle at all, or takes a twenty-minute nap and wakes cross. Too long, and settling gets harder rather than easier: an overtired baby is wired, not sleepy. Neither is damage. Both are information for the next attempt, and the next attempt is in about two hours.

The one thing worth resisting is the urge to fix a bad afternoon by rebuilding the whole day. Move one thing — usually the first window — by ten or fifteen minutes and give it three days before you decide it did not work.

The months where the shape changes

Awake time does not creep up smoothly. It sits still for weeks and then moves, usually around the point where a nap goes or a new skill arrives. These are the pages for each stage, with what is actually changing at that age and what to do about the problem that particular month tends to hand you.

• Newborn — 45 minutes to an hour, no clock, and a day built around feeds rather than naps.
• 2 months — an hour to an hour and a half, the evening fussing at its peak, four or five naps.
• 3 months — an hour and a quarter to an hour and three quarters, and the first naps that look like naps.
• 4 months — an hour and a half to two and a quarter, sleep cycles maturing, and the fourth nap starting to wobble.
• 5 months — the same band, held by a baby who has learned to roll and wants to practise it at 2am.
• 6 months — two to three hours, solids arriving, and the third nap on its way out.
• 7 and 8 months — two and a half to three and a half, crawling, and separation anxiety in the small hours.
• 9 to 12 months — three to four hours, pulling to stand, and the nap drop that is usually too early.
• Toddler — four to seven hours awake, one nap, and a bedtime that has opinions.

If what you are actually facing is a fortnight where nothing works, the regression timeline covers the ages where sleep commonly comes apart, and the nap transition checker is as willing to tell you to wait as it is to tell you to change the day.

Safe sleep, whatever the timing does

Wake windows are the trivial part of this subject and the sleep itself is the important part. Every sleep, day and night, however the timing went: babies go down on their back, on a firm flat surface, in a cot clear of blankets, pillows, bumpers and soft toys, in your room for at least the first six months. Nothing weighted goes on or over a sleeping baby. That does not change with the age at the top of the table.

And if what you are worried about is not the timing — feeding, weight gain, a baby who cannot be settled at all, a cry that does not sound like her usual one — that is a conversation with your pediatrician or health visitor. Nothing here is medical advice and no page can see your baby.