By age
- 2 months: 11 milestones, for example "Holds head up when on tummy" and "Makes sounds other than crying".
- 4 months: 13 milestones, for example "Holds head steady without support when you are holding her" and "Makes sounds like "oooo", "aahh" (cooing)".
- 6 months: 12 milestones, for example "Rolls from tummy to back" and "Takes turns making sounds with you".
- 9 months: 13 milestones, for example "Gets to a sitting position by herself" and "Makes different sounds like "mamamama" and "babababa"".
- 12 months: 10 milestones, for example "Pulls up to stand" and "Waves "bye-bye"".
- 15 months: 13 milestones, for example "Takes a few steps on his own" and "Tries to say one or two words besides "mama" or "dada," like "ba" for ball or "da" for dog".
- 18 months: 15 milestones, for example "Walks without holding on to anyone or anything" and "Tries to say three or more words besides "mama" or "dada"".
- 2 years: 13 milestones, for example "Kicks a ball" and "Points to things in a book when you ask, like "Where is the bear?"".
- 30 months: 15 milestones, for example "Uses hands to twist things, like turning doorknobs or unscrewing lids" and "Says about 50 words".
- 3 years: 12 milestones, for example "Strings items together, like large beads or macaroni" and "Talks with you in conversation using at least two back-and-forth exchanges".
- 4 years: 17 milestones, for example "Catches a large ball most of the time" and "Says sentences with four or more words".
- 5 years: 15 milestones, for example "Buttons some buttons" and "Tells a story she heard or made up with at least two events. For example, a cat was stuck in a tree and a firefighter saved it".
Movement milestones: the normal range is wide
The WHO Motor Development Study followed healthy children in five countries. These are the ages by which 1% and 99% of them reached each skill:
| Milestone | Earliest (1st percentile) | Latest (99th percentile) |
|---|---|---|
| Sitting without support | 3.8 months | 9.2 months |
| Standing with assistance | 4.8 months | 11.4 months |
| Hands-and-knees crawling | 5.2 months | 13.5 months |
| Walking with assistance | 5.9 months | 13.7 months |
| Standing alone | 6.9 months | 16.9 months |
| Walking alone | 8.2 months | 17.6 months |
About 4.3% of the children in the study never crawled on hands and knees, and the CDC checklists do not list crawling as a milestone.
When to act early
The CDC says: you know your child best. If your child is not meeting one or more milestones, has lost skills he or she once had, or you have other concerns, act early. Talk with your child's doctor, and ask for a developmental screening.
Sources: CDC, "Learn the Signs. Act Early." milestone checklists; WHO Multicentre Growth Reference Study Group, "WHO Motor Development Study: Windows of achievement for six gross motor development milestones," Acta Paediatrica 95 (2006): 86-95.
