Corrected Age Calculator
Free corrected age calculator for premature babies. Also used as a corrected gestational age calculator or premature corrected age calculator to adjust age for weeks born early.
Plain-language interpretation
Chronological age counts time since birth. Corrected age subtracts how early the baby was relative to a 40-week term reference, so developmental comparisons can use term-equivalent timing. Your care team decides when correction is appropriate.
Formula and data standard
Corrected age = chronological age − (40 weeks − gestational age at birth). Gestational age may include extra days (0–6). No growth-chart dataset is required for this arithmetic tool.
Applicable age range
Premature births with gestational age 22–42 weeks at birth. Many clinics stop correcting near 24 months corrected age; this site shows a note at that threshold but does not force a rule.
Worked example
Birth 2024-01-01, assessment 2024-07-01, GA 32+0 weeks: chronological age 182 days; prematurity 8 weeks (56 days); corrected age 126 days (18 weeks exactly).
Limitations
- Does not implement Fenton, Olsen, or other preterm growth charts.
- Does not replace clinician guidance on developmental assessment.
- Term reference fixed at 40 weeks (common convention).
References
- Clinical convention: corrected (adjusted) age = chronological age − weeks of prematurity relative to 40 weeks.
- CDC materials discussing corrected age in growth assessment context (educational link; WHO infant charts not implemented on this site).
FAQ
- What is a corrected gestational age calculator?
- It adjusts chronological age by the degree of prematurity relative to 40 weeks, often called corrected or adjusted age.
- Is this a premature corrected age calculator only?
- It is designed for infants born before term. Term births (near 40 weeks) yield little or no adjustment.
Content maintenance date: 2026-07-16. Editorial and methodology review: see Editorial and methodology review.