4-Month-Old Sleep Schedule

Your baby was finally starting to sleep in longer stretches. Maybe you even got a five-hour block last week and thought you'd turned a corner. Then, seemingly overnight, everything fell apart. Welcome to four months old.

Most 4-month-olds need about 14.5 hours of total sleep per day: roughly 10 hours at night and 4.5 during the day.¹² That number comes with a pretty wide range, though. The AASM recommends 12 to 16 hours for infants 4 to 12 months, naps included.³ The National Sleep Foundation says 12 to 15.⁴

How much sleep does a 4-month-old need?

A 2012 systematic review of 34 studies found that normal infant sleep ranged from about 9.7 to 15.9 hours.⁵ At 4 months specifically, longitudinal data from Bruni et al. shows most babies sleeping about 14 to 15 hours total, with nighttime sleep consolidating around 10 hours and daytime sleep making up the remaining 4 to 5 hours.¹

If your baby is closer to 13 and seems content, that's within range. If they're pushing 16, also fine. These are population averages. Your baby gets to be an individual.

Our sleep needs by age guide covers the full picture from newborn through toddlerhood.

Wake windows at 4 months

At 4 months, wake windows run about 1.5 to 2.3 hours (90 to 140 minutes). A typical window is around 2 hours (125 minutes).¹

The first wake window of the day is the shortest. Most 4-month-olds do best with about 1 hour and 45 minutes awake after their morning wakeup, roughly 15% shorter than a midday window.⁶ The last window before bedtime is a bit shorter than midday too, about 10% less. Overtired babies fight sleep harder, which makes the whole evening miserable for everyone.

Pay attention to sleepy cues: yawning, eye rubbing, zoning out, fussiness. At this age, the window between "pleasantly tired" and "overtired meltdown" is narrow.

Our wake windows chart has the numbers by age.

How many naps at 4 months?

Four. Sometimes five on a rough day. Individual naps tend to be short: 30 to 60 minutes each.¹

At this age, single-cycle naps (about 30 to 45 minutes) are biologically normal. A sleep cycle at 4 months lasts roughly 50 minutes, and many babies haven't learned to link cycles yet.⁷ If your baby consistently wakes after 35 minutes looking happy and alert, that nap was probably enough. If they wake cranky, they might need help connecting to the next cycle, or the wake window before that nap was off.

The 4-to-3 nap transition typically starts around 4 to 5 months, though the full range is 3 to 5.⁶ Signs it's happening: one of the naps keeps getting shorter or your baby starts refusing it outright. Don't force it. If some days are four naps and others are three, that's normal during the transition.

Check our nap transition guide for the details on when and how to drop naps.

A sample day

Times will shift depending on your baby's morning wake time. The structure and wake window spacing matter more than the exact clock times.

Time	Activity
7:00 AM	Wake up, first feed
7:30 AM	Play, tummy time
8:45 AM	Nap 1 (30 to 60 minutes)
9:30 AM	Wake, feed
10:00 AM	Play, sensory exploration
11:30 AM	Nap 2 (30 to 60 minutes)
12:15 PM	Wake, feed
12:45 PM	Play, outdoor time
2:15 PM	Nap 3 (30 to 60 minutes)
3:00 PM	Wake, feed
3:30 PM	Play, family time
5:00 PM	Nap 4 (20 to 40 minutes)
5:30 PM	Wake, feed
6:00 PM	Calm play, bath
7:15 PM	Bedtime routine (dim lights, pajamas, book, feed)
7:45 PM	Bedtime

Bedtime at 4 months is a bit later than it will be in a few months. The 7:30 to 9:00 PM range is typical here, shifting earlier as the circadian rhythm matures.⁸⁹ By 5 to 6 months, most families land closer to 7:00 to 8:00 PM.

The wake windows aren't all equal. Morning is the shortest (about 1 hour 45 minutes), midday windows stretch closer to 2 hours, and the pre-bedtime window tightens back down. That pattern is consistent across most pediatric sleep guidance for this age.⁶

On bad nap days (and there will be many), add an extra catnap or shift bedtime 30 minutes earlier. Protecting nighttime sleep is more important than sticking to a rigid daytime plan.

The 4-month sleep regression

This is the big one. If you've heard of only one sleep regression, it's probably this one. And unlike the others, it's not really a regression at all. It's a permanent upgrade to your baby's brain.

What's actually happening

During the newborn period, babies cycle between just two sleep states: active sleep (similar to REM) and quiet sleep. They also fall asleep directly into active/REM sleep, which is why newborns can drift off anywhere and seem to sleep through anything.⁷

Around 3 to 4 months, the brain reorganizes. Active sleep and quiet sleep differentiate into the same distinct stages adults have: light NREM (stages 1 and 2), deep NREM (stage 3, slow-wave sleep), and REM.⁷¹⁰ Sleep onset also flips. Instead of falling asleep into REM, babies now enter sleep through light NREM, just like adults do.⁹

This change is permanent. There's no going back to the simpler newborn pattern.

Why it wrecks sleep

The problem: between each new sleep cycle (roughly every 50 minutes), your baby now experiences a brief partial arousal. Adults do too, but we've spent decades learning to roll over and go back to sleep without fully waking. Your 4-month-old has had these new sleep stages for approximately zero days. Every cycle transition is a potential full wakeup.

That's why a baby who was sleeping 5- or 6-hour stretches suddenly starts waking every 45 minutes to 2 hours. Nothing is wrong with them. Their brain just rewired itself and they haven't figured out the new system yet.

How long does it last?

The regression window runs from about 3.5 to 5 months.² The acute rough patch, where sleep visibly deteriorates, typically lasts 2 to 6 weeks. Some families barely notice it. Others have a brutal month. Both are normal.

The architectural change itself is permanent, but the sleep disruption isn't. Once your baby learns to manage the new cycle transitions (whether with practice, time, or some help from you), sleep improves. Often it gets better than it was before, because those new deep-sleep stages are restorative in a way newborn sleep wasn't.

What you can do

You can't prevent or skip this one. But a few things help:

Keep wake windows appropriate. An overtired baby at this age wakes even more frequently. Aim for 90 to 140 minutes of awake time, with the first and last windows on the shorter end.

Make the room dark. Really dark. Melatonin production is still maturing at this age,⁹ and a pitch-black room supports the signal. White noise helps too.

If you don't have a bedtime routine yet, start one. Research shows a consistent nightly routine improves both infant sleep and parental wellbeing.⁸ Bath, pajamas, book, feed, bed. The consistency matters more than the specific steps.

When possible, put the baby down drowsy but awake. This isn't a hard rule. Think of it as giving your baby practice opportunities. The more chances they get to fall asleep from a drowsy state, the faster they figure out how to connect sleep cycles on their own.

Don't panic about naps. Short naps are fine. Contact naps are fine. Stroller, carrier, whatever gets your baby some sleep during a rough stretch. The regression is temporary.

Read more in our sleep regression guide.

Feeding and sleep at 4 months

Most 4-month-olds are still exclusively on breast milk or formula. The AAP and WHO recommend waiting until about 6 months for solids, though some pediatricians give the green light between 4 and 6 months if the baby shows readiness signs.¹¹

At this age, expect 6 to 8 milk feeds per day, with bottle-fed babies taking about 120 to 180 ml (4 to 6 oz) per feed.¹² Breastfed babies may feed more frequently and for shorter durations.

For night feeds: 1 to 3 per night is normal. Some 4-month-olds can stretch 4 to 6 hours between feeds overnight, but many still need to eat every 3 to 4 hours, especially breastfed babies.¹² The goal right now isn't to eliminate night feeds. It's to make sure your baby is eating enough during the day that the nighttime feeds are genuinely about hunger, not habit.

A loose guideline: if your baby falls back asleep quickly after a night feed (10 to 15 minutes), they probably needed it. If they're wide awake and want to play, the wakeup might be a sleep cycle transition issue rather than hunger.

Our feeding guide has amounts and schedules by age.

Common problems at this age

Every nap is 30 to 40 minutes. This is the single most common complaint at 4 months, and it's almost always normal. One sleep cycle at this age is about 50 minutes, and many babies wake at the 30- to 40-minute mark as they transition between cycles.⁷ It typically improves between 5 and 6 months as the brain gets better at linking cycles.

Bedtime takes forever. If your baby fights falling asleep for 30+ minutes, the wake window before bed might be wrong. Too long and they're overtired (wired, fussy, hard to settle). Too short and they're not tired enough. Adjust by 10 to 15 minutes in either direction and give it a few days.

Night wakes every 1 to 2 hours. Classic 4-month regression territory. If this started suddenly around 3.5 to 4 months, the sleep architecture change is almost certainly the cause. Focus on consistent responses and appropriate wake windows during the day.

One side of the night is terrible. Some babies sleep a decent first stretch (3 to 5 hours) and then wake hourly from 2 AM onward. This pattern happens because the first part of the night is NREM-heavy (deeper sleep), and the second half is more REM-heavy (lighter, more arousals).⁷ It's textbook sleep architecture at this age.

Frequently Asked Questions

Is it normal for a 4-month-old to only nap 30 minutes?

Yes. Completely normal. A sleep cycle at this age is about 50 minutes, and many babies wake during the lighter phase around the 30- to 40-minute mark.⁷ They haven't figured out how to bridge between cycles yet. It usually improves by 5 to 6 months.

When do babies go from 4 naps to 3?

Typically between 4 and 5 months, though the range is 3 to 5 months.⁶ The signs: one nap keeps getting shorter or your baby starts skipping it, wake windows are stretching naturally, and three longer naps fill the day better than four short ones. Let your baby lead. Some days will be four naps and others three during the transition period.

Can I sleep train during the 4-month regression?

Most sleep consultants recommend waiting until the acute regression phase passes before starting formal sleep training, usually around 5 to 6 months at the earliest. During the regression itself, focus on healthy sleep habits (consistent routine, dark room, appropriate wake windows) rather than strict methods. Trying to sleep train during a major neurological reorganization usually creates more stress than progress.

Should my 4-month-old have a set bedtime?

A loose one, yes. The circadian rhythm is functional by this age, and research shows that melatonin and cortisol begin cycling in a predictable pattern around 3 to 4 months.⁹ A consistent bedtime (within a 30-minute window) helps reinforce that rhythm. At 4 months, 7:30 to 9:00 PM is the typical range, trending earlier as your baby gets closer to 5 and 6 months.