4-Month Milestones to Know Before Sleep Training

By Kimberly


Knowing and tracking babies’ milestones is part of how we make sure that they’re progressing and growing up. At 4 months of age, the milestones are becoming even more fun to keep track of, even while you’re getting ready for sleep training.

Milestones for 4-month-old babies include new physical, emotional, language, and problem-solving skills. Your baby can see better, interact and babble, play with toys, mimic facial expressions, and communicate with different cries. By this time, babies may be ready for sleep training.

So if you want to know more about the milestones – and what to watch for so that you can start sleep training, then keep reading.

An image of a happy family with the father carrying a newborn baby while the mother leans next to her husband.

4-Month Milestones to Know and Track (before you can sleep train!)

Let’s look at the milestones your baby should reach at four months of age by type: physical, emotional/social, language/communication, and problem-solving/cognitive. Then, let’s add a fifth thing to watch: concerning signs to watch for.

That way, you’ll know exactly what’s expected and when there’s an issue that needs your pediatrician’s attention.

PhysicalEmotional and SocialCommunicationCognitiveConcerning Signs
Current weight should be about double that of their birth weightLikes to play and interact with peopleUses different cries to express themself (different cries for hunger, exhaustion, and pain)Recognizes family, close friends, and familiar things from a distance
Can hold up their head unsupportedWatches peopleHas begun to babble and “talk”Responds to people around them and to affectionCan’t hold their head steady
May be able to roll overSmiles at people on their ownTries to copy sounds they hearIs able to let you know if they are happy or sadDoesn’t smile at people
“Stands” (pushes down on legs) when feet are put on a hard surfaceCopies of some facial expressionsEnjoys watching faces – especially from up closeDoesn’t “stand” when feet are on a hard surface
Can bring their hand to their mouthBecomes sad (and maybe even cries) when playtime endsIs developing hand-eye coordination (is able to follow and reach for toys)Doesn’t (or can’t) bring things to their mouth
Able to hold a toyCan move eyes in all directions – especially side to sideMoving one or both eyes in any direction is difficult
Can push up to elbows from their tummyIs beginning to understand emotions via reading facial expressions and tone of voiceDoesn’t respond to sounds
Tries to grab at toys (usually a swing and a miss!)Can grab at toys with one handDoesn’t track movement (watch things as they move)
Requires 14-16 hours of sleep between nights and 2 naps

Now, if your baby was born prematurely, remember to adjust for that.

So if they are 4 months old but were born a month early, they may not be reaching these milestones yet – and that’s totally normal. They’ve got another month to get here before you need to be concerned.

Does My 4-Month-Old Need to See the Doctor?

If your baby isn’t meeting the average 4-month milestones or you’re concerned, go see the doctor. Otherwise, see your doctor at regular well-child checkups, where they’ll be screened using developmental milestones.

The American Academy of Pediatrics recommends that children be screened for general development using standardized, validated tools at 9, 18, and 24 or 30 months and for autism at 18 and 24 months or whenever a parent or provider has a concern. Ask your child’s doctor about your child’s developmental screening.

Centers for Disease Control and Prevention

But if you’re ever concerned or your parental intuition says something is off, don’t ever feel bad about consulting with your doctor.

And if you’re concerned about your baby not meeting milestones? Hold off on any sleep training until you’ve consulted your pediatrician.

How Far Can a 4 Month Old See?

Most four-month-old’s vision is the equivalent of 20/40 vision. They can see objects from across the room and pick out details. They can see and recognize familiar people and things from across the room.

However, they still prefer to people-watch from close up. And they especially love watching facial expressions! By now, they’re even trying to mimic them. So sidle up to your baby and start making faces. Because they’ll try to make them back.

What Can I Feed My 4-Month-Old?

Officially, the American Academy of Pediatrics recommends exclusively breastfeeding (or bottle-feeding) until a baby is six months old. However, many doctors also say it’s okay to start introducing solid foods to children by 4-6 months of age (click here to see what the Mayo Clinic says).

So if your baby is interested in food and can sit up (with some help), then you may want to start introducing some basic single-ingredient baby cereals and foods.

Just be sure to start with single-ingredient foods – whether cereals, fruits, or vegetables. That way, your baby’s digestive system isn’t completely overwhelmed and stopped up by the change in what they’re eating.

It’s also important to just do one food at a time so you can watch for potential food allergies.

Can My 4-Month-Old Drink Water?

A four-month-old baby can drink up to 2 ounces of water within any 24-hour period. It’s a great way to teach them to use a sippy cup.

Two ounces is the maximum recommendation, though, so that they aren’t filling up on water and losing out on essential calories. These babies still require calorie-rich breastmilk or formula as their main beverage.

4-Month Olds and Sleep Milestones

At 4 months of age, a baby’s brain takes a significant developmental turn: it matures from a disorganized sleeping pattern into a more adult-like one.

What this means is that babies can start sleeping better by about 4 months of age, and they may even be ready for dedicated sleep training. So let’s talk about some of the most important sleep milestones for these cute kiddos.

Can My 4-Month-Old Sleep Through the Night?

Many 4-month-olds can sleep through the night – to a degree.

They are physically and neurologically capable of sleeping 6-9 hours at a stretch each night. And some babies can sleep a full 12 hours.

However, the average baby may still need feeding at the 6-9 hour mark. After eating, many babies will be able to go right back to sleep for another few hours.

An image of a baby girl sleeping on the couch.

How Much Sleep Does My 4-Month-Old Need?

A 4-month-old baby needs between 14-16 hours of sleep within a 24-hour period. Most of this sleep will be at night, although your baby will also take naps.

How Often Should a 4-Month-Old Nap?

Most 4-month-olds take 2 naps each day. The exact timing will depend on schedules and other factors. But most 4-month-olds take a morning and an afternoon nap.

Will All 4-Months-Old Sleep Well?

Not all 4-month-old babies will sleep well, no. Some will take another few months to settle into a regular, reliable sleeping pattern – whether you sleep train them or not.

Is There a 4-Month-Old Sleep Regression?

At 4-6 months of age, babies’ brains mature – this causes a change in sleep that’s often called a sleep regression. However, not all babies have a noticeable change in their sleeping patterns.

So it depends.

  • Some babies will have no noticeable change in their sleep at 4 months old.
  • Some babies will become better sleepers at 4-6 months of age.
  • And some babies will get worse at sleeping at this age. It could be a temporary thing or it could become a learned behavior and the new normal.

For more information on what to do about the 4-month-old sleep regression, make sure you read my complete guide to the 4-month sleep regression right here on Sleep Training Kids.

Can I Sleep Train My 4-Month-Old?

Yes, you can. By 4-6 months old, babies can successfully be sleep trained. If you’d like to see my best sleep training resources, you can get them via this site – or read my article on when to start sleep training (with a month-by-month analysis).

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