Baby Age Calculator
Track every precious moment. Calculate your baby's age in precise units and view growth milestones.
How It Works
Enter Birth Date
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Why EaseToolz?
Baby Age Calculator — Exact Age in Weeks and Months
Parents need to know their baby's age in weeks (first few months) and then months — not just "born in March." Pediatricians use exact ages for developmental milestone tracking, vaccination schedules, and nutrition guidance.
Quick answer: Enter your baby's date of birth above. The calculator shows exact age in days, weeks, months, and years. For school admission eligibility, use the "Age As Of Date" feature with the school's cut-off date.
Baby Age Chart — First Year
| Age | Days | Developmental Stage |
|---|---|---|
| Newborn | 0–7 days | Feeding, sleep establishment |
| 2 weeks | ~14 days | Weight regained to birth weight |
| 1 month | ~30 days | Social smiling begins |
| 2 months | ~61 days | Head control developing |
| 3 months | ~91 days | Batting at objects |
| 4 months | ~122 days | Rolling attempts |
| 6 months | ~183 days | Solid foods introduction |
| 9 months | ~274 days | Pulling to stand |
| 12 months | ~365 days | First birthday 🎂 |
Why "4 Weeks" ≠ "1 Month"
This confuses most new parents. Four weeks = 28 days exactly. One calendar month = 28, 29, 30, or 31 days — depending on which month. Pediatricians always use calendar months (same date, next month), not 4-week blocks.
A baby born on the 15th is 1 month old on the next 15th — regardless of whether that is 30 or 31 days later.
Premature Baby — Corrected Age
If born prematurely, use corrected age for developmental milestones:
Formula: Corrected age = Chronological age − Weeks premature
Example: Born 8 weeks early → chronological age 6 months → corrected age 4 months
Most pediatricians stop using corrected age at 24–36 months, when the gap becomes less clinically significant.
School Admission Age — Key Cutoffs
| State | Nursery | LKG | Class 1 |
|---|---|---|---|
| Delhi | 3 years by March 31 | 4 years by March 31 | 5 years |
| Maharashtra | 3 years by June 30 | 4 years by June 30 | 5 years |
| Karnataka | 3 years by June 1 | 4 years by June 1 | 6 years |
| Tamil Nadu | 3 years by June 30 | 4 years by June 30 | 5 years |
Related Tools
- Full Age Calculator — complete age stats including heartbeats and planetary age
- Age As Of Date Calculator — check eligibility for any specific cut-off date
- What Generation Am I — find your generational cohort
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