Chronological age and corrected age
Chronological age is the time elapsed since the actual date of birth. Corrected age—sometimes called adjusted age—is an estimate that subtracts the amount of prematurity. For example, if a baby is chronologically 20 weeks old and was born 8 weeks early, the simple corrected-age estimate is 12 weeks.
Formula
Corrected age = chronological age − weeks premature. This tool converts the remaining elapsed days into calendar years, months, and days for readability.
Medical limitation
This calculator is educational and is not a medical device. Definitions of full term, the number of weeks to subtract, rounding, and the age at which adjustment is discontinued may vary by clinician and purpose. Do not use this result for diagnosis, treatment, medication, feeding, emergency decisions, or interpreting development without a qualified pediatric professional.
If you are unsure of gestational age or weeks premature, use the figure documented by the baby's healthcare team rather than estimating it from memory.