The 4 to 3 Nap Transition

Most babies come down from four naps to three somewhere around three to five months, and the reason is arithmetic rather than a birthday: the fourth nap is a catnap, and once awake stretches stretch past an hour and a half there is no longer room in the day for it. The sign worth acting on is time — the same nap refused, or cut to almost nothing, for two weeks or more. One bad week is a bad week. When the fourth nap does go, bedtime comes forward rather than later, and that early bedtime does most of the work.

This is the gentlest of the three transitions, and the one that usually happens to you rather than the one you arrange. It is also the one most often mistaken for something else: three to five months is a crowded stretch, and a fortnight of ragged evenings at this age has several plausible causes of which only one is a nap.

Why the fourth nap goes first

Look at the day as a container rather than a list. A baby of three months is awake somewhere between an hour and a quarter and an hour and three quarters at a time; by four or five months that has grown to an hour and a half to a bit over two hours. Those are wide bands, they overlap, and the wake windows by age page shows where they come from — they are compiled from published total-sleep figures, not quoted from any table, because no health body publishes a wake-window chart.

Now do the sum. Four naps means five awake stretches between morning wake-up and bed. At an hour and a quarter each that is a day of roughly thirteen hours, which fits. At two hours each it is nearly seventeen, which fits inside nobody's evening. Something gives, and what gives is the last and shortest sleep of the day — the twenty or thirty minutes late in the afternoon that was never a proper nap.

You usually see it in this order. The catnap gets harder to get: she lies in the pram looking pleased with herself, or takes ten minutes instead of thirty. Then bedtime drifts — half past seven, then eight, then half past. Then one day the catnap does not happen and, if bedtime is brought forward to meet it, the evening is the best it has been for a fortnight. That is the whole transition; it does not announce itself.

Bedtime comes forward, not later

This is the part the tidy schedules get backwards, and it is the single most useful thing on this page. When a sleep comes out of the day, the day gets shorter, not longer. The gap the catnap used to fill has to go somewhere and the cheapest place to put it is the front of the night.

So on the days the fourth nap does not happen, bedtime moves earlier — often by half an hour, sometimes more. A bedtime that feels absurdly early for a couple of weeks is not a problem to be corrected; it is the shock absorber, and an early night after a short day tends to produce a better morning than a late night after a long one.

The reverse is the trap. If you push bedtime out to nine o'clock in order to fit a catnap in, you are asking a five-month-old to manage a fifteen-hour day for the sake of a twenty-minute sleep in the middle of it. The catnap costs more than it pays.

False starts: down at seven, awake at eight

The false start is the classic symptom of this stage, and it is worth naming precisely because it is so easily read as the opposite of what it is. A false start is a baby who goes down at seven, sleeps deeply for forty minutes to an hour, and is then up and awake — not grizzling herself back to sleep, but properly awake, often cheerful, and impossible to resettle for an hour.

Almost always that is telling you the last awake stretch was wrong, not that she is finished with her naps. Two versions of wrong produce the same evening:

• The stretch before bed was too short. A catnap that ended at half past five followed by a seven o'clock bedtime gives an hour and a half of awake time to a baby who now needs two. There is not enough pressure to sleep, so she surfaces at the end of the first cycle and stays up.
• The stretch before bed was far too long. No catnap at all, four hours awake, and a baby arriving at bedtime past the point of settling. She crashes, then wakes an hour later wired.

The fix is the same in both cases and it is small: move one thing by fifteen minutes and give it three or four nights before you judge it. If the false start follows a catnap, either cap the catnap or push bedtime fifteen minutes later. If it follows a long afternoon with no sleep in it at all, bring bedtime fifteen minutes earlier. Rebuilding the whole day usually just moves the problem somewhere you cannot see it.

The bridging nap, and why it is not a failure

For a fortnight or so in the middle of this, most families end up with something in between: a short sleep at about five o'clock in a pram, in a carrier or on you, purely to get from the last real nap to bedtime without the last hour falling apart.

That is a legitimate tool and it is worth saying so plainly, because the genre tends to treat it as backsliding. A bridging nap is how you buy an evening. Use it on the days that need it, skip it on the days that do not, and expect to stop needing it within a couple of weeks as the awake stretches lengthen.

One caveat, and it is the important one: a sleep on you or in a pram needs an adult awake and watching. Every sleep where nobody is watching — every nap in a cot and every bit of the night — happens the same way: on her back, on a firm flat surface, in a cot clear of blankets, pillows, bumpers and soft toys, in your room. Nothing weighted goes on or over a sleeping baby.

Expect alternating days, for weeks

Very few babies do this in one step. Three-nap days and four-nap days alternate, apparently at random, for two to four weeks: a morning nap that runs long gives you a three-nap day, a short first nap gives you a four-nap day and a later bedtime.

Keep both versions available rather than picking one and defending it. The sleep schedule generator draws both from the same age so you can see the two shapes side by side, and the wake window calculator gives you the band to aim the last stretch at. Neither prints a single clock time, because neither knows one.

If you have taken the fourth nap out and the next fortnight is worse rather than better — bedtime a fight, early mornings, a baby who is cross from four o'clock onwards — put it back. That is allowed, and trying again in three weeks usually works. Dropping a nap early costs a fortnight of bad evenings and nothing more permanent.

What else is happening at three to five months

Two published things sit right on top of this transition, and both look like nap trouble from the outside.

The first is that babies do not have regular sleep cycles until about four months, according to the American Academy of Pediatrics — so around that age the shape of sleep itself changes, and a baby who used to sleep through anything starts surfacing between cycles. That is the stretch the internet calls the four-month regression; our page on it explains why nobody this site may cite uses that word, and what is actually published instead.

The second is movement. The AAP puts rocking on the stomach, kicking and swimming with the arms at about five months, and those are the skills that add up to rolling. A baby who has just learned to roll will practise it at two in the morning, in the dark, with enthusiasm. This is also the point at which the cot needs to be genuinely empty and any swaddle needs to stop, because a swaddled baby who can roll cannot use her arms.

If your fortnight of bad nights lines up with either of those, the naps are probably not the problem. The nap transition checker is built to make exactly that distinction: it asks what you are seeing and how long it has been going on, and it is as willing to say wait as to say change the day.

Where this sits in the sequence

The by-month pages carry the detail either side of this one: three months, four months and five months. After this comes the messier one — three naps down to two, somewhere around six to nine months, where two naps do not yet reach bedtime on their own.

None of this is medical advice and no page can see your baby. If what worries you 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 rather than a nap question.