Baby Age Calculator

Track your baby's exact age in months and weeks — and see which developmental milestones are coming up next.

Baby Developmental Milestones

AgeKey Milestones
1 monthFollows objects with eyes, responds to sound
2 monthsSocial smiling begins
4 monthsHolds head steady, laughs
6 monthsSits with support, starts solid foods
9 monthsCrawling, pincer grasp developing
12 monthsFirst steps, first words
18 monthsWalking well, vocabulary growing
24 monthsTwo-word phrases, runs confidently

Frequently Asked Questions

Why is baby age counted in months?

Infant development happens so rapidly that a 3-month-old and a 9-month-old are at completely different developmental stages — years alone are far too coarse a measure.

When does a baby become a toddler?

Generally around 12–18 months, when walking begins. The toddler stage is typically considered ages 1–3 years.

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