The Growing Child: 4 to 6 Months

How much will my baby grow?

While all babies may grow at a different rate, the following is the average for boys and girls 4 to 6 months of age:

  • Weight. Average gain of 1 to 1¼ pounds each month; by 4 to 5 months has doubled birth weight

  • Height. Average growth of ½ to 1 inch each month

  • Head size. Average growth of about ½ inch each month

What can my baby do at this age?

This age is very social, and babies start moving in much more purposeful ways. Babies may progress at different rates. But these are some of the common milestones most babies reach in this age group:

  • Grasp, Moro, root, and tonic neck reflexes (reflexes normally present in young infants) disappear

  • Balances head well

  • Leans on hands to support when sitting

  • Pushes up with straight arms when on tummy

  • Rolls from tummy to back by 6 months

  • Starts drooling (not always a sign of teething)

  • Naps 2 to 3 times a day, for 1 to 3 hours each (on average)

  • Starts to sleep longer at night (6 to 8 hours consistently)

  • Has full-color vision, able to see at longer distances

What can my baby say?

It's very exciting for parents to watch their babies become social beings who can interact with others. Every baby develops speech at their own rate. But these are some of the common milestones most babies reach in this age group:

  • Takes turns making sounds with you

  • Laughs

  • Squeals

  • Blows bubbles or "raspberries"

What does my baby understand?

A baby's awareness of people and surroundings increases during this time, and they may start to interact with people other than their parents. Babies may progress at different rates. But these are some of the common milestones most babies reach in this age group:

  • Knows familiar things and people

  • Puts things in their mouth to explore them

  • Reaches to grab a toy they want

  • Closes lips when they don't want more food

  • Likes to look at self in a mirror

How to help increase your baby's development and emotional security

Here are some ways to foster your baby's emotional security:

  • Repeat sounds and smile when your baby makes sounds.

  • Laugh with your baby.

  • Talk to and imitate your baby during feeding, dressing, changing diapers, and bath time.

  • Spend time on the floor playing with your child every day.

  • Dance with your baby and do other rhythmic movements.

  • Introduce your baby to other children and parents.

  • Place safe toys near your baby to encourage reaching and grasping.

  • Encourage laughing and play by making funny faces or sounds or blowing on baby's belly and laughing.

  • Play peek-a-boo games to help develop object permanence, the understanding that objects are still present even though they can't be seen.

  • Show your baby bright picture books and interesting objects.

  • Show your baby their reflection in a mirror.

  • Read books and stories to your baby, and point out pictures.

  • Take your baby outside to see new things and people.

  • Hold your baby for feedings and cuddle when they are awake.

  • Hold and comfort your baby when they are unhappy.

Online Medical Reviewer: Dan Brennan MD
Online Medical Reviewer: Liora C Adler MD
Online Medical Reviewer: Stacey Wojcik MBA BSN RN
Date Last Reviewed: 8/1/2023
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