Date & Time
Age, duration & timezone calculators
Baby Age Calculator (age in weeks and months)
Find out how many weeks and months old a baby is — the way new parents, paediatric visits and parenting apps actually count age in the first months of life. Enter the baby’s date of birth and the as-of date and the calculator divides the total days lived by seven to give the whole weeks, and also shows the calendar-month count. For example, a baby born on 1 April 2026, as of 24 June 2026, has lived 84 days — that is exactly 12 weeks, or about 2 months and 23 days. Reading age in weeks is standard up to a few months, after which months become the natural unit. All the math runs on UTC midnights so a day is always a full calendar day regardless of a daylight-saving change, and everything is computed in your browser. If you need to adjust a premature baby’s age for prematurity, switch to the corrected-age mode.
Weeks = floor(total days lived / 7); months = calendar-month count
- Born 1 Apr 2026, as of 24 Jun 2026 = 84 days = 12 weeks (≈ 2 months 23 days)
- Switch to corrected age to adjust a preterm baby for prematurity
Frequently asked questions
How many weeks old is my baby?
Divide the total number of days your baby has lived by seven and take the whole number. A baby born on 1 April 2026 is 84 days old on 24 June 2026, which is exactly 12 weeks (about 2 months and 23 days). The calculator shows the whole weeks and the calendar-month count.
When should I count a baby’s age in weeks versus months?
Age is usually tracked in weeks for the first couple of months — for feeding, growth and early milestones — then in months up to about two years. This tool shows both so you can use whichever your paediatrician or parenting app expects.