Adjusted Age Calculator
Babies born early are often assessed by their adjusted age — the age they would be if they had been born on their due date. Enter the birth date and original due date.
- Adjusted (corrected) age
- 0 years, 5 months, 21 days
- Chronological age
- 0 years, 7 months, 16 days
- Born early by
- 8 weeks
- Gestational age at birth
- about 32 weeks
Pediatricians typically use adjusted age for milestones until about age 2 (24 months).
Worked example
Example: born March 1, 2026, due April 26, 2026
- Born 56 days = 8 weeks early (about 32 weeks' gestation)
- Chronological age on Oct 17, 2026: 7 months, 16 days
- Adjusted age = age counted from the due date: 5 months, 21 days
Adjusted age is about 5½ months.
Formula
Adjusted age = Chronological age − Weeks premature
Weeks premature = (Due date − Birth date) ÷ 7
Adjusted age is typically used for growth and developmental milestones until about age 2 (24 months).
Frequently asked questions
Is adjusted age the same as corrected age?
Yes, the terms are interchangeable.
When do you stop adjusting age for prematurity?
Most pediatricians stop at 2 years, though some continue to age 3 for very premature babies.
Should vaccines follow adjusted age?
No. Vaccines are usually given by chronological age. Ask your pediatrician.
Last reviewed October 17, 2026 · Calculations run in your browser; nothing you enter is sent to a server.