Dr. BabyFree corrected age calculator
Adjusted age
calculator.
For babies born early, adjusted age adds context. See chronological and corrected age side by side.
Two ages.
One little person.
Enter dates to see actual age, corrected age and estimated due date.
Adjusted age and corrected age mean the same thing.
Chronological age counts time since birth. Corrected age subtracts how early your baby was born, using a 40-week pregnancy as the calculation reference.
Corrected age = chronological age − (40 weeks − gestational age at birth).
For example, a baby born at 32 weeks was 8 weeks early. At 16 weeks since birth, the corrected age is 8 weeks. If the estimated due date has not yet arrived, the tool shows the time remaining instead of presenting a negative developmental age.
This calculator is for babies born from 22 weeks through 36 weeks and 6 days. Ask your clinician how long to use corrected age for your baby; this is not a vaccination scheduler.
Method: American Academy of Pediatrics · Corrected Age for Preemies ↗
A useful place to start
How to use this tool
- Enter the date of birth and gestational age at birth in completed weeks plus additional days.
- Choose the date on which to calculate age.
- Compare chronological age, corrected age and the estimated due date. Before the due date, the result shows time remaining.
Questions about adjusted age calculator
Are adjusted age and corrected age the same?
Yes. Both names describe chronological age minus the time a baby was born before the 40-week reference. You do not need separate calculators for those terms.
How is corrected age calculated in weeks and days?
The calculation first uses days: chronological days − [280 − (gestational weeks × 7 + additional days)]. The result is then displayed in weeks and days.
Why does the calculator show time until the due date?
If the calculation falls before the estimated due date, corrected age would be negative. The tool shows the remaining weeks and days instead.
Can this set vaccination dates?
No. It explains an age calculation. It does not create a vaccination schedule or an individual developmental assessment.
Content updated · Methods, sources & limitations