Age in Months
—
— months and — days old
—Years
—Total Days
—Total Weeks
Why Track Age in Months?
During infancy and early childhood, monthly age tracking is standard medical practice. Pediatricians, developmental specialists, and standardized assessment tools all use age in months rather than years because development happens so rapidly during this period.
Key Developmental Age Ranges (in Months)
0–3 months
Newborn — lifts head, tracks faces, responds to sound
4–6 months
Infant — rolls over, sits with support, first foods
7–9 months
Crawler — sits alone, pincer grasp, begins babbling
10–12 months
Pre-toddler — pulls to stand, first words, waves bye-bye
12–18 months
Early toddler — walks, 5–20 words, uses spoon
18–24 months
Toddler — runs, 2-word phrases, pretend play
Note: Developmental ranges are general guidelines. Always consult a pediatrician for individual assessment.
Frequently Asked Questions
How do I calculate my baby's age in months?
Enter your baby's date of birth in the calculator above. It will show the exact number of completed months, plus the remaining days. For example, a baby born on March 15 would be exactly 6 months old on September 15.
Why do doctors ask for age in months for young children?
During the first two years, infants and toddlers develop rapidly. A 12-month-old and an 18-month-old have significantly different abilities and needs, even though both would be called "about a year old." Monthly precision allows accurate developmental screening and comparison to milestone charts.
When do doctors switch from months to years?
Most pediatricians begin using years and months (e.g., "2 years, 3 months") after age 2. By school age, just years are typically sufficient, though months may still be noted for certain assessments through age 5.
Can I use this for corrected age in premature babies?
This calculator shows chronological age in months. For premature babies, doctors often track "corrected age" (also called adjusted age) — chronological age minus weeks of prematurity. Use our
Corrected Age Calculator for that calculation.