Bottom line up front: at four months, most babies do best with 90 to 120 minute wake windows, three to four naps, and 10 to 12 hours of night sleep — and the infamous regression is a permanent change in how your baby sleeps, not a phase that passes on its own. Here is the template I used, backed by research and personal experience with a baby who fought me on all of it.
Wake windows at 4 months
Wake windows — the stretch of awake time between sleeps — are the real schedule at this age; clock times are just where the windows happen to land. At four months the workable range is 90 to 120 minutes, but the windows are not all the same length:
| Window | Typical length | Notes |
|---|---|---|
| Wake-up to nap 1 | ~90 minutes | Reliably the shortest of the day |
| Between naps 1–3 | 105–120 minutes | The midday stretch tolerates the most flex |
| Last nap to bedtime | ~120 minutes | Guard this one — overtired bedtime unravels the night |
Two practical rules I learned the hard way. First, count the window from eyes-open to actually-asleep, not to “we started walking upstairs” — the 15 minutes of routine is part of the window. Second, when a nap is short (under 45 minutes), shorten the next window by 15 to 20 minutes; a cat-napped baby cannot run a full window.
If your baby is a little younger or older than four months, do not force these numbers — the full chart from birth to two years is in my wake windows by age guide, including how the windows stretch month by month.
Reading tired cues alongside the clock
Watch the baby, not just the clock: rubbing eyes, going quiet, staring into the middle distance, and losing interest in the toy that was fascinating 30 seconds ago all mean start the nap routine now, not after you finish the dishes. By four months, fussing and arching are late cues — if you regularly see those before naps, shift the whole schedule about 15 minutes earlier for a few days and the naps usually lengthen on their own.
Sample day
| Time | What’s happening |
|---|---|
| 7:00 am | Wake, feed, play |
| 8:30 – 9:45 am | Nap 1 |
| 9:45 am | Feed, play |
| 11:30 am – 12:45 pm | Nap 2 |
| 12:45 pm | Feed, play |
| 2:30 – 3:30 pm | Nap 3 |
| 3:30 pm | Feed, play |
| 5:15 – 5:45 pm | Catnap 4 (often in the carrier or stroller) |
| 6:30 pm | Bath, feed, books |
| 7:15 pm | Down for the night |
| 1 – 2 night feeds | Still completely normal at this age |
Treat the times as anchors, not commandments. The wake windows are the real schedule; the clock times drift with the first wake-up. On a 6:15 wake-up day, everything slides earlier and the fourth catnap becomes non-negotiable; on a 7:45 day, nap three may stretch and the catnap disappears. Both are fine.
About that fourth catnap
The 4-to-3 nap transition usually happens somewhere in the four-to-five-month range, and it announces itself: the catnap gets fought, or bedtime starts drifting past 8:00. When that happens on most days for a week, drop the catnap, pull bedtime as early as 6:30 for a stretch, and let the remaining three naps absorb the day. An early bedtime feels drastic; it is the release valve that makes the transition painless.
Surviving the regression
The four-month regression is your baby’s sleep cycles maturing into adult-style stages — which means more brief wakings between cycles, forever. That sounds bleak, but it reframes the problem correctly: the babies who sail through are the ones who can fall asleep without being fully assisted, because they can repeat the trick alone at 2 a.m. What worked in my house:
- Put her down awake for the first nap of the day. It is the easiest one to practice on; bedtime is the hardest.
- Pick one soothing step to remove per week, not all of them at once. We went from rock-to-asleep, to rock-to-drowsy, to pat-in-crib.
- Hold bedtime steady even when naps implode. A consistent 7:00 to 7:30 bedtime saved us more nights than any product I tested.
- Take shifts. The regression lasts two to six weeks. Two half-rested parents beat one destroyed one.
- Keep night feeds boring. Lights low, no chat, straight back down. The skill you are protecting is the fall-back-asleep, and a 2 a.m. social hour undoes a week of practice.
No swaddle transition product, special mattress, or $60 sound machine fixed this stage — practice at falling asleep did. This is also the age where families who bought a motion bassinet hit its weight-and-rolling limits and have to wean off it anyway; I covered that timing trap in Is the Snoo worth it?. Save your money for diapers and coffee.
FAQ
How long should a 4-month-old’s naps be?
Anything from 30 minutes to 2 hours is normal at this age, and most babies land a mix: one or two long naps and one or two short ones. Aim for 3.5 to 4.5 total daytime hours rather than judging any single nap. Chronic 30-minute naps across the whole day usually mean the wake windows are slightly off — adjust in 15-minute steps.
What time should a 4-month-old go to bed?
Most land between 6:30 and 8:00 pm, set by counting roughly two hours from the end of the last nap. The bedtime that matters is the relative one — clock-perfect 7:00 after a failed nap day produces an overtired disaster, while a “shockingly early” 6:15 bedtime after nap chaos usually buys a full night.
How many night feeds are normal at 4 months?
One to two, and holding onto them through the regression is completely normal. The regression makes wakings more frequent, but wakings and feeds are different things — feed the hungry ones, practice the fall-back-asleep on the rest. If night feeds are multiplying rather than shrinking, that is usually a schedule or independent-sleep issue wearing a hunger costume.
Is the 4-month regression really permanent?
The neurological change is permanent — cycle-based sleep with brief arousals is how your baby will sleep for the rest of their life, which is why “wait it out” underdelivers. The symptoms are absolutely fixable: once a baby can fall asleep independently, the arousals become invisible again. That skill is the entire game.
If you have a younger baby and want to see how you get to this point, start with the newborn sleep schedule — and if you’re still in the buying stage, my minimalist registry lists the five sleep items that are actually worth owning.
