Adjusted Age Calculator

Calculate corrected/adjusted age for premature babies. Used for milestone tracking and growth chart comparisons until age 2-3.

Results

Visualization

How It Works

Adjusted (corrected) age accounts for prematurity by subtracting the weeks born early from the actual age. A baby born at 32 weeks is 8 weeks early, so at 20 weeks old, their adjusted age is 12 weeks. Use adjusted age for milestone and growth comparisons until age 2-3. Not medical advice.

The Formula

Adjusted Age = Actual Age - (40 - Gestational Age at Birth)
Weeks Early = 40 - Gestational Age

Variables

  • 40 weeks — Full-term gestational age
  • Adjusted age — The age baby would be if born at full term

Example

Born at 32 weeks, now 20 weeks old: 40 - 32 = 8 weeks early, adjusted age = 12 weeks (about 3 months).

Tips

  • Most preemies catch up to peers by age 2-3
  • Use adjusted age for growth charts, milestones, and feeding decisions
  • Very premature babies (under 28 weeks) may need adjusted age longer
  • Your pediatrician and early intervention team will guide milestone expectations
  • Preemies often have their own unique growth trajectory -- consistency matters more than percentile

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