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 birthweight

  • 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 your baby may reach in this age group:

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

  • Balances head well

  • Sits with support, back is rounded

  • Starts to support body with legs when held in standing position

  • Rolls from back to front and front to back by 6 months

  • Moves object from one hand to other

  • Grabs feet and toes when lying on back

  • Makes "swimming" motions with arms and legs when placed on belly

  • 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 is 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 in this age group:

  • Coos and gurgles when talked to, or in response to toys

  • Babbles, imitates sounds

  • By 6 months, makes single syllable sounds (da, ma, ba)

  • 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 parents. Babies may progress at different rates. But these are some of the common milestones in this age group:

  • Recognizes familiar things and people

  • May hold out arms to be picked up

  • Begins to learn concept of object permanence (such as a partly hidden object under a blanket is still there)

  • May show displeasure when object or person goes away

  • May recognize their own name

  • May start to understand "no"

  • Starts to understand cause and effect (the sound a toy makes when it is dropped)

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

Here are some ways to foster the emotional security of your baby:

  • 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: Amy Finke RN BSN
Online Medical Reviewer: Heather M Trevino BSN RNC
Online Medical Reviewer: Liora C Adler MD
Date Last Reviewed: 2/1/2021
© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.