Corrected Age Calculator
This corrected (adjusted) age calculator finds a premature baby's developmental age by subtracting the weeks of prematurity from the chronological age. Corrected age is used to fairly track growth and milestones in preterm infants.
Calculator
LiveEnter values to see your result.
How to Use the Calculator
- Enter the baby's date of birth.
- Enter the gestational age at birth in weeks and days.
- Read the chronological and corrected (adjusted) age.
What the Result Means
Corrected age reflects where a premature baby would be developmentally if born at term. Use it — not the chronological age — when assessing growth and developmental milestones, typically until 2–3 years of age.
When to Use This Calculator
- Tracking development in preterm infants
- Interpreting growth charts for preemies
- NICU and pediatric follow-up visits
Frequently Asked Questions
What is the difference between corrected and chronological age?
Chronological age is time since birth. Corrected age subtracts the weeks a baby was born early (40 weeks minus the gestational age at birth), giving a fairer basis for assessing development.
How long do you correct for prematurity?
Corrected age is typically used until 2–3 years of age, after which the difference becomes clinically negligible for most children.
References & Guidelines
- AAP. Age terminology during the perinatal period (adjusted age).