Adjusted age calculator
For babies born before 37 weeks: work out corrected age from the birth date and how early your baby arrived, so you compare growth and milestones fairly.
Enter a birth date.
Why correct for prematurity?
A baby born 10 weeks early spent those weeks growing outside the womb instead of inside it. Compared with babies born at term on the same day, they'll look small and "behind", but compared with babies due on the same day, they're usually right on track. Corrected age makes that fair comparison. You can apply it directly in the baby percentile calculator (it has a "born early" option) and use it with the milestone checklists.
Frequently asked questions
What is adjusted (corrected) age?
Your baby's age counted from their due date instead of their birth date. A baby born 8 weeks early who is 5 months old has a corrected age of 3 months. Corrected age is used to assess growth and development for premature babies.
Until what age should I use corrected age?
Usually until 2 years (24 months chronological age). By then most preterm babies have caught up. Some clinicians stop earlier for babies born only a few weeks early. For very preterm babies, follow your neonatal team's advice.
Do premature babies get vaccines on corrected age?
No. Vaccines are given by chronological age (from birth), even for premature babies, according to the CDC and AAP. Corrected age is for growth charts, milestones and, often, starting solids.
Which age should I use for starting solids?
Many neonatal teams suggest starting solids around 6 months corrected age (and not before about 4 months corrected), watching for readiness signs like good head control and sitting with support. Ask your baby's care team.