If your baby was born early, doctors often use their corrected age (also called adjusted age) to check growth and development. Enter the date of birth and the number of weeks of pregnancy at birth, and the calculator shows both the actual age and the corrected age.
General information from online sources, not written by a doctor and not a substitute for individual medical advice. Recommendations may differ by country; ask your care team about your baby.
How corrected age is calculated
Corrected age = actual age − the number of weeks your baby was born before 40 weeks. A baby born at 32 weeks arrived 8 weeks early, so at 6 months old their corrected age is about 4 months.
| Born at | Weeks early | At 6 months old, corrected age is about |
|---|---|---|
| 36 weeks | 4 | 5 months |
| 32 weeks | 8 | 4 months |
| 28 weeks | 12 | 3 months |
When to use corrected age
Corrected age is used for milestones (smiling, sitting, crawling) and often for growth charts, usually until about 2 years of age. Vaccinations, however, are normally given by actual age. Your baby's medical team will tell you which age to use for what.
Comparing with baby milestones or the growth percentile calculator? Use the corrected age your doctor recommends.
Every premature baby follows their own path. If you are worried about development or feeding, talk to your pediatrician or your neonatal follow-up team.
Keep everyone on the same page
Premature babies often have more appointments and more people helping at home. In the baby tracker app Trackeron the whole care circle can log feeds, sleep and weight in real time (family sharing is part of Premium).
Track your preemie's growth and feeds
Log weight, feeds and sleep in Trackeron and bring clear charts to every follow-up visit. Free to download.
Frequently asked questions
What is corrected age?
Corrected (adjusted) age is your baby's age counted from the due date instead of the birth date. It equals actual age minus the number of weeks born before 40 weeks of pregnancy.
Until what age should I use corrected age?
Usually until about 2 years, when most premature babies have caught up. Your pediatrician will advise for your baby.
Are vaccines given by corrected age?
In general no — vaccines are normally given by actual (chronological) age. Follow your doctor's schedule.
My baby was born at 38 weeks. Do I need corrected age?
Babies born at 37 weeks or later are considered full term, so corrected age is usually not used.
Is my data stored?
No. Everything is calculated in your browser.