Baby Month By Month

3 Month Old Baby

Your baby is 3 months old!

What a charmer! By 3 months, baby is probably smiling plenty, and she's likely started to imitate what she hears and sees (so watch what you do, mama!). You should chat with her throughout the day, describing what you're doing, how you're doing it and where you're going—this is how she'll eventually learn to talk! Just don't go too crazy tough. Baby is a quick learner, but she needs you to keep things clear and simple, and to recognize when she needs a break.

3-Month-Old Development

Baby is becoming even more active and social at three months, isn’t she? She’s more in control of her body and more aware of people and interacting with them, which makes for lots of fun at playtime.

3-Month-Old Baby Weight & Length
Parents want to know: How much should a 3-month-old weigh and measure? The average weight of a 3-month-old baby is 12.9 pounds for girls and 14.1 pounds for boys; average length is 23.5 inches for girls and 24.2 inches for boys.

Whether baby’s close to the average or not, the important thing is that she’s growing at a healthy rate. She's likely gained another 1.5 to 2 pounds and grown 1 to 1.5 inches this month. The size of her head may have gone up by a half inch, too.

It’s common for a baby to experience a 3-month-old growth spurt. Signs of a growth spurt are having an especially hungry or cranky baby. Baby might wake more at night too. Don’t worry—growth spurts are temporary! Let baby eat, sleep or cuddle more if that’s what she seems to want, and try not to get too frustrated by the sudden change.

Five Senses

At 3 months old, baby’s senses have developed rapidly.

  • She's working at becoming a great communicator, making eye contact with you, and she can now recognize your face.
  • She follows moving objects with her eyes.
  • She smiles when she hears your voice.

3-Month-Old Milestones
What Should a 3-Month-Old Be Doing?

  • She's mimicking some sounds, movements and expressions and starting to babble.
  • Let baby play on the floor or under a baby gym, since she loves to kick up a storm and swing at things.
  • A 3-month-old at tummy time probably raises her head and her chest, holding up her upper body with her arms.
  • She opens and closes her hands.
  • When you hold her upright, she’ll push down with her feet onto the floor or your lap.
  • She bats at hanging toys above her.
  • She can grasp and shake a toy.

Look out for these signs of a developmental or medical problem at three months; they’re worth a call to the doctor:

  • Baby doesn’t respond to loud sounds or smile at the sound of your voice.
  • Baby doesn’t follow moving objects with her eyes.
  • Baby doesn’t smile socially.
  • Baby can’t grasp or hold objects.
  • Baby doesn’t bring her hands or objects to her mouth.
  • Baby’s eyes still seem crossed most of the time.
  • Baby doesn’t babble.
  • Baby doesn’t pay attention to new faces.
  • Baby doesn’t push down with her feet when she’s held upright and they’re placed on a flat surface.

Is My 3-Month-Old Healthy?
There are lots of health questions parents of three month olds have. Below are some of the most common, with links to detailed articles to help you answer them.

3-Month-Old Feeding

In the last couple months, baby’s appetite has certainly increased! And she knows how to tell you when she’s hungry. Of course, you’ve probably gotten in such a routine with feeding that you know when she’s about to do that hungry cry.

How much should a 3-month-old eat?

Bottle feeding: How much formula for a 3-month-old baby? Typically five ounces about six to eight times a day.

Breastfeeding: How often should a 3-month-old nurse? Feedings are typically about every three or four hours at this age but each breastfed baby may be slightly different. What’s important is that baby seems content, your boobs seem to have been emptied (they’re soft) and baby’s gaining weight healthily.

To double-check that baby’s getting enough breast milk, you can check her diapers. How many wet diapers for a 3-month-old baby? About four or five very wet ones per day.

You may notice your 3-month-old eating less than she did previously. Breastfed babies do get more efficient, so it’s normal for your baby to feed in about half the time it took her to feed as a newborn. If you see all the signs that baby’s getting enough to eat, it’s perfectly normal. If not, it could be a sign of a problem, so talk to the pediatrician.

What Can Baby Eat This Month?
Baby is still only able to eat breast milk and/or formula. Many parents ask Can I give my 3-month-old water? Nope! Most doctors recommend parents wait until baby’s ready for solid foods—around 4 to 6 months of age—before they get water. Baby’s getting plenty of hydration from breast milk or formula and needs the nourishment it provides.

3-Month-Old Feeding Schedule

Photo: Megan Rubey

3-Month-Old Sleep

How long do 3-month-olds sleep and nap?
Three-month-olds typically sleep about 15 hours a day, and more of those hours are falling at night. In fact, it’s common for 3-month-olds to sleep about 10 hours at night, maybe with at least one five- or six-hour stretch. Baby is probably taking three naps totaling five hours of daytime sleep.

How can I get my 3-month-old to sleep?
It’s harder than you might think to get a tired baby to actually go to sleep! You’ve probably heard the usual advice: Keep the room dark and cool, rock and sing to your baby, and put baby to sleep while he’s sleepy but not yet asleep. Still there are some nights when none of that seems to work. Try some other moms’ tried and true tricks for calming a fussy baby; they just might help you get your little one to snooze—finally.

What should my 3-month-old’s bedtime be?
The ideal bedtime for a 3-month-old baby depends on your family’s schedule, but many experts believe around 7 to 9 p.m. is ideal at this age. As baby begins to sleep for longer stretches at night, you’ll want to gradually make bedtime earlier, which (surprisingly!) encourages baby to sleep even longer.

Does my 3-month-old have sleep regression?
You may notice a bit of 3-month-old sleep regression. Baby might be waking more often at night because of a growth spurt, or it might be a developmental thing. Around 3 or 4 months, babies’ brains are becoming more alert and because of that, they want to be using that brainpower more often. Growth spurts can last a few days but true sleep regression (which typically happens closer to 4 months) can last two to six weeks.

3-Month-Old Sleep Schedule

Photo: Megan Rubey

3-Month-Old Schedule

A 3-month-old baby is a creature of habit—bedtime, nap and feeding routines keep her happy.

3-Month-Old Schedule Example
A 3-month-old’s daily schedule might look something like this.

Photo: Megan Rubey

3-Month-Old Baby Checklist / Tips

  • Make sure you have your four-month baby checkup scheduled. There’s no well-baby visit this month.
  • Look for signs of readiness for eating solid foods. The pediatrician may recommend you start as early as four months.
  • If you’re going back to work after maternity leave, best wishes, mama. You got this!
  • How often should I bathe my 3-month-old baby? Don’t worry about giving baby a bath more than once every few days.
  • Find some new things to do with your 3-month-old baby.
  • Take baby’s 3-month-old baby photo.