If your baby was born before 37 completed weeks, corrected age can help you make sense of developmental milestones. Their actual age counts from the day they were born. Corrected age counts from the due date, allowing for the weeks they arrived early.
A simple example
A baby who is 16 weeks old and was born 6 weeks before their due date has a corrected age of about 10 weeks. You subtract the 6 weeks early from their actual age.
How to use it here
Enter your baby’s birthday and the expected due date recorded by your care team. The timeline can then show a corrected-age marker alongside their actual age. It applies to developmental notes where corrected-age guidance is relevant.
The calculation treats the due date as 40 weeks of pregnancy. It offers correction when the dates suggest birth before 37 completed weeks, at least 22 days early. Before the due date, the display stays at birth rather than showing a negative age. If the result differs from your medical record, ask your care team to help check the dates.
How long is corrected age useful?
UK NICE guidance uses corrected age to assess development in the first two years. This site stops displaying correction on the second birthday. That is a limit of this timeline, not an instruction to stop follow-up: some children have an assessment at two years corrected age, which falls later. Keep the appointments your care team recommends.
Feeding, sleep and growth need their own advice
This timeline does not automatically move feeding, sleep, crying or growth information to match corrected age. Your care team considers your baby’s health and birth history as well as their dates. In particular, ask when to start solid food if your baby was born early.
Your browser uses the dates to show the timeline. We do not receive them, and you do not need an account. You can clear saved details from the timeline at any time.
If you are worried about development
Corrected age gives useful context, but it cannot assess your baby’s development. If a skill is missing at its stated age, your baby loses a skill or something worries you, speak with your health visitor or doctor. You do not need to wait for the next chapter.