Preemie Adjusted Age Calculator
Corrected age is used for babies born before 37 weeks to track development accurately.
Chronological Age
(Actual time since birth)
Adjusted Age
(Age based on due date)
If a baby is born prematurely, developmental milestones—like crawling or smiling—should be tracked using Adjusted Age. This is the age the baby would be if they were born on their original due date. This prevents parents from worrying about "delays" that are actually biologically on track.
For example, if a 6-month-old was born 2 months early, their adjusted age is 4 months. Use this tool until your child reaches age 2, then switch to the Standard Age Calculator. You can also find their very first Half-Birthday using their actual birth date for celebration.
Common Questions about Adjusted Age
When do I stop adjusting?
Most experts recommend using adjusted age until the child reaches two years of age.
Why is adjusted age important?
It provides a realistic developmental baseline based on their Gestational Age history.
Do I use this for vaccines?
No. Vaccines are typically given based on chronological age. Check the Age Calculator for that.
How does this affect school?
Check our School Start Calculator for enrollment guidelines.
Can I see my baby's age in seconds?
Yes, use the Age in Seconds Tool.
Is it the same as conception age?
No. Conception usually happens 2 weeks after the date used for Gestational Age.