Enter your baby's date of birth and today's date to get a complete age breakdown — see exactly how many years, months, weeks, days, hours, and minutes old your little one is. The Baby Age Calculator also shows upcoming milestone markers for the first two years so you can track your newborn's development at a glance.
Baby's Age in Months
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Years
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Months
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Total Weeks Old
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Total Days Old
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Total Hours Old
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Next Milestone
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The first two years of a baby's life are critical for physical and cognitive development. Tracking your baby's age in months helps ensure they receive vaccinations on schedule, meet developmental milestones on time, and get appropriate nutrition and care for each growth stage. Pediatricians use month-based age to assess growth percentiles and developmental progress.
Simply enter your baby's date of birth in the first field. The calculator will automatically use today's date as the reference, then display your baby's age in years, months, weeks, days, and hours. You can also change the reference date to see how old your baby will be on a future date like a birthday or holiday.
The calculator shows the total number of days from your baby's birth date to today. For example, a baby born exactly 3 months ago is roughly 90–92 days old depending on the months involved. The exact count depends on the specific calendar dates.
Total weeks are calculated by dividing the total days old by 7. A 3-month-old baby is approximately 13 weeks old, while a 6-month-old is around 26 weeks. Weeks are particularly important in the newborn stage for tracking feeding patterns and developmental leaps.
An 18-month-old baby is 1 year and 6 months old, approximately 78 weeks or 547 days old. At this stage, most toddlers are beginning to walk steadily, say several words, and show signs of independent play.
An 8-month-old baby is approximately 34–35 weeks old. The exact number depends on the specific birth date and calendar months involved, since months vary in length between 28 and 31 days.
There are exactly 24 months in two years. The baby age chart typically covers milestones through 24 months (2 years) because this period is considered the most rapid phase of development in a child's life.
Most parents and pediatricians track age in weeks for the first 3 months (12 weeks), then switch to months up to age 2. After 2 years, age is typically expressed in years and half-years. This calculator shows all units simultaneously so you always have the most useful figure for your baby's stage.