Baby Age Calculator
Find your baby's exact age in months, weeks, and days from their birth date. Precise age tracking for milestones, pediatric check-ups, and developmental stages — free and instant.
Why Baby Age in Months Matters
During the first two years of life, age is tracked in months rather than years because development happens so rapidly. Pediatricians, child health nurses, and developmental specialists all assess milestones relative to a baby's age in months. Knowing your baby's precise age helps you:
- Track developmental milestones against age-appropriate benchmarks
- Know when vaccinations are due (typically at 2, 4, 6, 12, and 18 months)
- Determine when to introduce solid foods (around 6 months)
- Complete paperwork for childcare, healthcare, or government programs
Developmental Milestone Reference
These are general milestones. Every child develops at their own pace — consult your pediatrician with any concerns.
1 month
Follows objects with eyes, responds to sounds
2 months
Social smiling, holds head up briefly
4 months
Laughs, reaches for objects, steady head control
6 months
Sits with support, babbles, rolls both ways
9 months
Sits independently, crawls, waves bye-bye
12 months
Stands, says first words, pincer grasp
18 months
Walks steadily, vocabulary of 10–20 words
24 months
Runs, 2-word phrases, about 50+ words
Frequently Asked Questions
How do I calculate my baby's age in months?
Enter your baby's birth date into the calculator. It instantly shows the exact age in months and days — the standard way to track infant development milestones.
How old is a baby born today in weeks?
A baby born today is 0 weeks old. Our calculator shows exact age in weeks and days from any birth date, updating in real time.
When does a baby's age switch from weeks to months?
Most healthcare providers track age in weeks for the first 12 weeks (3 months), then switch to months up to age 2, and years thereafter. Our calculator shows all three simultaneously.
How is corrected age calculated for premature babies?
Corrected (adjusted) age is calculated by subtracting the number of weeks premature from the baby's actual age. For example, a 3-month-old born 6 weeks early has a corrected age of about 1.5 months.
Is a baby age calculator accurate?
Yes. Our calculator is accurate to the exact day, accounting for varying month lengths and leap years. It matches the calculation method used by pediatricians and child health nurses.