Adjusted Age Calculator for Preemies

Method (American Academy of Pediatrics): weeks early = 40 weeks − gestational age at birth (weeks + days). Corrected age = actual age − weeks early, counted on the calendar from the term-equivalent date (birth date + weeks early).

Range: gestational age 22w0d–42w6d is accepted. Correction applies only to preterm birth (before 37 weeks); at 37 weeks or more corrected age equals actual age. It is normally used for development during the first 2 years. Before the term-equivalent date the tool shows days remaining and postmenstrual age instead of a corrected age.

Dates: plain calendar dates in your local calendar; months use the last day of short months (Jan 31 + 1 month = Feb 28/29). The birth date must not be after the calculation date. Reset clears the inputs and sets the date back to today. This is not medical advice.