A Review of Milestones and Your Baby's Growth Chart
When welcoming a new baby into the world, ensuring their having appropriate weight gain and meeting developmental milestones can feel overwhelming. Pediatric specialists Jenny Olson, DNP, and Sarha DeVrieze, ARNP, UnityPoint Clinic, share what parents should know about baby milestones and growth based on their age.
Baby Growth Chart
How Much Weight Should a Newborn Gain?
Growth charts are percentile curves showing body measurements, such as weight, length and head circumference. Pediatric providers, nurses and parents use growth charts to track the growth of infants, children and teens. By themselves, growth charts aren’t intended for diagnosing health problems. If your baby is outside average measurements, it doesn’t always indicate a problem. Growth charts are simply a helpful measurement that are one part of your baby’s overall health.
“We use the growth chart at every visit to ensure children are appropriately growing for their age,” Olson says. “It’s a helpful visual when discussing feedings and determining if there's a need to boost nutrition, which is essential at this age.”
To view the Center for Disease Control and Prevention growth charts and calculate the growth for your child, visit cdc.gov/growthcharts.
Average Baby Boy Weight by Month
| Boy Age | Weight Average |
|---|---|
| Birth | 5 to 10 lbs |
| 3 months | 10 to 16 lbs |
| 6 months | 13.5 to 17.5 lbs |
| 9 months | 17 to 25 lbs |
| 12 months | 18.5 to 28 lbs |
| 15 months | 20 to 30 lbs |
| 18 months | 21 to 32 lbs |
Average Baby Girl Weight by Month
| Girl Age | Weight Average |
|---|---|
| Birth | 5.5 to 9 lbs |
| 3 months | 9.5 to 15 lbs |
| 6 months | 12.5 to 20 lbs |
| 9 months | 15.5 to 23 lbs |
| 12 months | 17.5 to 25 lbs |
| 15 months | 19 to 28 lbs |
| 18 months | 20 to 30 lbs |
When do babies double their birth weight?
On average, a baby will double their birth weight between four to six months. Pediatricians use this as a benchmark, but the timeline can vary based on different factors. For an average full-term baby weighing around 7.5 lbs at birth, doubling their birth weight means reaching about 15 lbs by four to six months. Premature babies make take longer, doubling their birth weight closer to six months.
Baby Developmental Milestones
How your child interacts and learns, through play and communication, offers important clues about their development. However, every child is unique. Some babies may reach milestones sooner or later than others. Routine screenings at specific ages are part of your child’s well-child check. Your provider will chat with you about any additional support for your baby’s growth, if needed.
Routine Developmental Screenings Parents Complete:
The American Academy of Pediatrics recommends children are screened using standardized, validated tools at nine,18, 24 and 30 months and whenever a parent or provider has a concern. Some screenings include Ages & Stages Questionnaires (ASQ), Survey of Well-being of Young Children (SWYC) and Modified Checklist for Autism in Toddlers (MCHAT).
"You can easily and naturally observe your baby's development when playing and caring for them," DeVrieze says. "We're here to help you track and trend their developmental milestones as they grow, and help with any concerns along the way."
Two Months
Around two months old, your baby looks at your face, smiles when talked to or smiled at, holds their head up when on their tummy, moves their arms and legs, reacts to loud noises and coos or babbles (makes vowel-like noises.)
Four Months
Around four moths old, your baby smiles on their own, chuckles (not yet a full laugh), turns their head towards sound of voice, makes cooing sounds, looks at hands with interest, brings hands to their mouth, pushes up on their elbows/forearms when on their tummy and teething may begin from four months to seven months, on average.
Five Months
Around five months old, your baby develops improved color vision.
Six Months
Around six months old, your baby likes to look at themselves in a mirror, laughs, blows “raspberries”, puts things in their mouth to explore, reaches to grab toys, rolls from tummy to back, leans on their hands to support when sitting and can start drinking water (4 to 8 oz—about 236.59 ml—per day.)
Eight Months
Around eight months old, your baby "commando crawls" (uses arms and legs to move forward while stomach stays on the ground) and holds a bottle without help.
Nine Months
Around nine months old, your baby makes facial expressions, recognizes names, looks when their name is called, lifts their arms to be picked up, makes different sounds, bangs things together, sits up without support, moves things from hand to hand and has the eye color they will have for the rest of their life.
Twelve Months
Around twelve months old, your baby plays games, waves, calls a parent by name, understands “no”, looks for items that are hidden, pulls up to stand, walks with assistance and drinks from a cup (with no lid.)
Fifteen Months
Around fifteen months old, your baby copies other children while playing, claps when excited, hugs dolls or toys, shows affection, can say one or two words, points to ask for something or get help, stacks small objects, takes a few steps and uses fingers to feed his or herself.
Eighteen Months
Around eighteen months old, your baby points to show something, looks at pages in books, helps dress oneself, can say three or more words, copies you, walks independently, tries to use a spoon and climbs on and off furniture without help.
When to See a Doctor if Your Baby’s Not Hitting Developmental Milestones
If your child isn’t meeting the milestones for his or her age, or if you think there’s a problem with how your child plays, learns, communicates, acts or moves, talk to your child's provider. You know your child best, and early intervention makes a big difference. Before and between routine well-child checks, take notes about any concerns you have and share them with your child's doctor at their next appointment.