Baby Age in Weeks Calculator

Free baby age calculator in weeks. Track your baby's age week by week from birth. Perfect for development milestones and checkups.

Track your baby's age in weeks—the preferred way to measure infant development during the first year. Enter your baby's birthdate and see their current age in weeks and days.

Common use cases

  • Parents tracking infant development
  • Pediatric appointment scheduling
  • Baby milestone tracking
  • Premature baby adjusted age calculations
  • Development comparison with guidelines

How to use

  1. Enter your baby's date of birth
  2. View their age in weeks and days
  3. See upcoming week milestones
  4. Track development stages
  5. Set reminders for checkups

FAQ

Why measure babies in weeks?

Infant development happens rapidly. Weekly tracking gives more precise developmental milestone comparisons than months.

What about premature babies?

For preemies, you can calculate both chronological age and adjusted age (from due date).

Until what age should I use weeks?

Weeks are most useful until about 12-16 weeks. After that, months become more practical.