Corrected Age for Preemies

About this calculator

Corrected age (also called adjusted age) accounts for how early a baby was born by subtracting the number of weeks of prematurity from their chronological age: corrected age = chronological age − (40 weeks − gestational age at birth). A baby born at 32 weeks who is 4 months old chronologically, for instance, has a corrected age closer to 2 months, since they missed 8 weeks of in-utero development.

Pediatricians use corrected age rather than chronological age when tracking a premature baby's growth, motor skills and developmental milestones on standard growth charts for roughly the first 2 years of life, because comparing a preemie's raw birth-date age against full-term norms would make normal development look delayed. Parents of preemies use it for the same reason — to set realistic expectations for milestones like rolling over, sitting up or first words.

This calculator takes a baby's birth date, due date and today's date and returns both chronological and corrected age.