What Is Corrected Age?

Corrected age (also called adjusted age) refers to the age a premature baby would be if born at full term (40 weeks). It’s essential for understanding developmental milestones, especially in babies born before 37 weeks of gestation.

Why Use a Corrected Age Calculator?

If your baby was born preterm, their actual age might not reflect their developmental progress accurately. Pediatricians and health professionals use corrected age to:

• Evaluate growth
• Track milestones (sitting, crawling, walking)
• Align developmental expectations

How the Corrected Age Calculator Works

Our Corrected Age Calculator uses three simple inputs to deliver accurate developmental age:

Target Date (optional)
By default, this is today’s date. You can change it to any future or past date to find the corrected age on that specific day.

Date of Birth (Actual)
This is the real birth date of your baby—regardless of whether they were born early.

Gestational Age at Birth
Enter how many weeks into pregnancy your baby was born (e.g., 32 weeks, 35 weeks, or 37 weeks). Full term is considered 40 weeks.

Calculation Formula Used

The tool uses this medically accepted formula:

Corrected Age = Actual Age (in weeks) – (40 – Gestational Age at Birth)

For example:

• If your baby was born at 32 weeks (8 weeks early)
• And is now 16 weeks old

Corrected Age = 16 – (40 – 32) = 8 weeks
So, your baby’s developmental age is 8 weeks (2 months), not 4 months.

Output

The calculator instantly shows:

• Total actual age (from birth to target date)
• Corrected age in months and days
• A friendly explanation for parents and caregivers

Trusted by Health Experts

This calculator is built referencing guidelines from the NHS, American Academy of Pediatrics, and Pearson neonatal tracking standards. It is especially useful for:

• Parents tracking milestones
• Neonatal health checkups
• Educational psychologists (e.g., Pearson assessments)
• Pediatricians & healthcare providers

Frequently Asked Questions (FAQs)

What is a corrected age calculator?

A corrected age calculator is a tool used to determine the developmental age of a premature baby. It adjusts the actual age based on how early the baby was born, helping parents and doctors better track growth and milestones.

How do you calculate corrected age for premature babies?

To calculate corrected age:

Corrected Age = Actual Age in Weeks – (40 – Gestational Age at Birth)

For example, if a baby is now 16 weeks old but was born at 32 weeks (8 weeks early), the corrected age is 8 weeks (2 months).

Why is corrected age important for preterm babies?

Corrected age is important because preterm babies may not meet developmental milestones at the same time as full-term babies. Using corrected age gives a more accurate picture of your baby’s growth, feeding patterns, and cognitive development.

What gestational age should I enter in the calculator?

Enter the number of weeks your baby completed in the womb before birth. A full-term baby is born at 40 weeks. If your baby was born at 28, 30, or 37 weeks, enter that exact value in the calculator.

Is this calculator based on NHS or medical guidelines?

Yes. The corrected age calculator aligns with neonatal care standards from trusted organizations including the NHS, American Academy of Pediatrics, and Pearson assessments used in early child development tracking.

What if my baby was born at 37 weeks? Do I still need corrected age?

If your baby was born at 37 weeks, they are technically considered “early term” rather than preterm. Most babies born at 37 weeks don’t need corrected age calculations unless recommended by a pediatrician due to developmental delays or low birth weight.

Can I use this calculator after 1 year of age?

Most pediatricians recommend using corrected age up to 2 years of age for preemies. After that, most children catch up to their full-term peers, and corrected age is usually no longer needed.

Does this calculator work for Pearson assessments?

Yes. The adjusted age calculator Pearson professionals use is based on the same concept—subtracting prematurity from actual age. Our calculator provides results compatible with educational and developmental assessments used by psychologists and therapists