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: The First 18 Months
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.
Two Months Old
- Looks at your face
- Smiles when talked to or smiled at
- Reacts to loud noises
- Holds head up when on tummy
- Moves arms and legs
- Coos or babbles (makes vowel-like noises)
Four Months Old
- Smiles on their own
- Chuckles (not yet a full laugh)
- Turns head towards sound of voice
- Makes cooing sounds
- Looks at hands with interest
- Brings hands to mouth
- Pushes up on elbows/forearms when on their tummy
- Teething may begin from four months to seven months, on average
Five Months Old
- Develops improved color vision
Six Months Old
- Likes to look at self in mirror
- Laughs, blows “raspberries”
- Puts things in mouth to explore
- Reaches to grab toys
- Rolls from tummy to back
- Leans on hands to support when sitting
- Can start drinking water (4 to 8 oz (about 236.59 ml) per day)
Eight Months Old
- Commando crawls (uses arms and legs to move forward while stomach stays on the ground)
- Holds bottle without help
Nine Months Old
- Makes facial expressions
- Recognizes names, looks when name is called
- Lifts arms to be picked up
- Makes different sounds
- Bangs things together
- Sits up without support
- Moves things from hand to hand
- Has the eye color they will have for the rest of their life
One Year Old (Twelve Months)
- Plays games
- Waves
- Calls a parent by name
- Understands “no”
- Looks for items that are hidden
- Pulls up to stand
- walks with assistance
- Drinks from a cup (with no lid)
Fifteen Months Old
- 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
- Uses fingers to feed his or herself
Eighteen Months Old
- 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 spoon
- Climbs on and off furniture without help
When to See a Doctor if Your Baby’s Not Hitting 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.
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."