← All Calculators

Baby Milestones

What milestones should your baby reach at each age? Pick an age or enter a birth date and get an overview by CDC framework — motor, language, social, cognitive.

This overview is not a substitute for routine well-child visits. Every child develops at their own pace — these milestones are markers, not pass/fail tests.

Ad

Daily nutrition made simple — vitamins, probiotics & adaptogens in one scoop.

Try AG1
Reference checkpoint:6 months

Motor

  • Rolls over in both directions
  • Sits with support
  • Passes objects from one hand to the other

Language

  • Responds to own name
  • Strings vowels together when babbling (aaaah, ohhh)

Social / Emotional

  • Knows familiar faces
  • Enjoys playing with others

Cognitive / Learning

  • Explores things by putting them in mouth
  • Shows curiosity — tries to get out-of-reach things

Watch out — when to call the pediatrician

Talk to your pediatrician if at this age your baby:

  • !shows no affection for caregivers
  • !doesn't reach for objects
  • !can't sit even with help

Average size at this age

Weight

7.6 kg

Length

66 cm

WHO median for healthy babies (averaged across sexes). Variation is normal — the growth curve in your child's chart is more meaningful than a single point.

How this overview works

This overview is based on the CDC's revised 2022 milestones (Learn the Signs. Act Early.) and the AAP/Bright Futures developmental surveillance recommendations. The eight reference ages (2, 4, 6, 9, 12, 15, 18, 24 months) align with US well-child visit checkpoints. For an age between two checkpoints, the nearest lower one is shown. Use corrected age for premature babies.

Important: every child develops differently. This list does not replace well-child visits or pediatric assessment. If your baby loses skills they once had (skills loss) or several milestones are clearly missed, talk to your pediatrician.

Frequently Asked Questions

What are developmental milestones?+
Milestones are typical developmental skills most children reach by a certain age. The CDC, for example, lists 'sits without support' as a 9-month milestone because ≥ 75 % of children reach it by then.
My baby hasn't reached a milestone yet — is that bad?+
Usually not. Babies develop in spurts and at their own pace. A single delayed milestone is rarely a problem, but several missed milestones or a loss of skills already gained should be discussed with the pediatrician.
Should I correct age for premature babies?+
Yes. For premature babies (born before 37 weeks of gestation), use corrected age — i.e. age from the original due date instead of the actual birth. The AAP recommends correction up to 2 years of age.
What sources are these milestones based on?+
The list follows the CDC's revised 2022 overview (Learn the Signs. Act Early.) and AAP Bright Futures recommendations. The CDC partnered with the AAP and specialists in pediatrics and developmental assessment to produce the revision.
When should I see the pediatrician?+
If your baby loses skills, doesn't react to sounds, doesn't make eye contact, doesn't smile or babble, or if your gut tells you something is off. The simplest rule is: when in doubt, ask.
What is the right tracking cadence?+
Well-child visits at 2, 4, 6, 9, 12, 15, 18, 24 months align with this framework. They are the standard touchpoint and most insurance plans cover them fully. Between visits, occasional informal tracking is enough — there's no need to test every day.
Can exercises speed up development?+
You can support development by talking, reading, floor playtime and safe spaces to explore. Speeding it up beyond a child's biological pace is rarely possible — development follows a genetically guided plan.

Background

Baby Milestones 0–24 Months — What Babies Do When

9 min