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Corrected age calculator for premature babies
Corrected age is your baby's age counted from the due date rather than the birth date. Enter the birth date and either the weeks of pregnancy at birth or the due date to see corrected age and actual age side by side, plus the day your baby reaches each corrected month.
Enter the birth date and either the weeks of pregnancy at birth or the original due date. Nothing is sent anywhere.
Every month counts, the early ones too
Little turns each week and month of the first year into a milestone photo with an age badge and a line about what changed, and keeps it on your Home Screen. Free for iPhone and iPad, no account.
What corrected age means
A baby born 8 weeks early spent those 8 weeks growing outside the womb instead of inside it. Development tends to follow the due date, not the birthday, so a 6 month old born at 32 weeks is often doing what a 4 month old does. Corrected age makes that comparison fair, and it is what health visitors and paediatricians usually use when they check milestones like sitting, babbling and crawling.
This calculator is for working out the dates. It is not medical advice, and your baby's care team will know which age to use for feeding, vaccinations and development checks. Vaccinations, for example, normally follow actual age.
Corrected age example
A baby born on 1 March at 32 weeks was due on 26 April, 8 weeks later. On 1 September the baby is 6 months old, and 4 months and 6 days corrected. Their first corrected month falls on 26 May, and their corrected first birthday on 26 April the following year.
For milestone photos, the actual-age dates are in the baby milestone calendar, and our newborn weekly photo ideas work just as well for the weeks before the due date. The weeks to months converter helps when the hospital talks in weeks and everyone else in months.
Corrected age questions
How do you calculate corrected age?
Take your baby's actual age and subtract the number of weeks they were born early. Weeks early is 40 minus the weeks of pregnancy at birth, so a baby born at 32 weeks is 8 weeks early. At 6 months old, that baby's corrected age is about 4 months.
Until what age do you use corrected age?
Usually until about 2 years old. By then most premature babies have caught up, and the few weeks' difference stops mattering. Your baby's doctor may advise a different cut-off, especially for babies born very early.
Is corrected age the same as adjusted age?
Yes. Corrected age and adjusted age mean the same thing: age counted from the due date instead of the birth date. Actual age is also called chronological age.
Does a baby born at 37 weeks need a corrected age?
Generally not. Babies born from 37 weeks are considered term, and corrected age is mainly used for babies born before 37 weeks. The calculator still shows the difference if you want to see it.
Which age goes on a premature baby's milestone photos?
Most parents photograph by actual age, because the monthly photos mark the months you have lived through together, NICU weeks included. Some add the corrected age to the caption as well, which makes the development story easier to follow later.