Adjusted Age Calculator for Premature Babies

Calculate corrected age to track your preemie's development accurately

Baby's Birth Date

Original Due Date

Calculate Age On

Understanding Adjusted Age

Adjusted age (also called corrected age) is calculated from your baby's original due date, not their actual birth date. This gives a more accurate picture of where your premature baby should be developmentally.

Premature babies need extra time to catch up because they missed out on important growth that would have happened in the womb. Using adjusted age helps set realistic expectations and reduces unnecessary worry about milestones.

When to Use Adjusted Age

Adjusted age should be used for:

Tracking developmental milestones (sitting, crawling, walking)
Speech and language development expectations
Growth chart interpretations
Early intervention assessments
Comparing development to age-based norms

Important: Always use chronological age (actual birth date) for vaccinations and medication dosages.

How Long to Adjust

Most healthcare providers recommend using adjusted age until your child reaches age 2. By this point, most preterm babies have caught up developmentally with their full-term peers. However, for very premature babies (born before 28 weeks), some providers may continue adjustments a bit longer.

Frequently Asked Questions

Adjusted age (also called corrected age) accounts for prematurity by calculating age from the original due date rather than the actual birth date. This gives a more accurate picture of developmental expectations for premature babies, whose development timeline starts later than full-term babies.

Most pediatricians recommend using adjusted age for developmental milestones until the child is 2 years old. After age 2, most preterm children have caught up developmentally, and chronological age is typically used. However, some healthcare providers may continue adjustments longer for very premature babies.

To calculate adjusted age, subtract the number of weeks the baby was born early from their chronological age. For example, if a baby is 12 months old and was born 8 weeks early, their adjusted age is approximately 10 months (12 months minus 2 months).

No, vaccinations should be given according to chronological age, not adjusted age. The immune system develops based on time since birth, not gestational age. Always follow your pediatrician's vaccination schedule based on the actual birth date.

Premature babies should reach developmental milestones according to their adjusted age, not chronological age. For example, if your baby was born 2 months early, expect them to reach the 6-month milestones around 8 months of chronological age. This is normal and expected.

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