Wonder Weeks Calculator

Track your baby's developmental leaps

Baby Information

Click to select year, month, and day
For more accurate results, use the due date rather than the actual birth date

What are Wonder Weeks?

The Wonder Weeks is a theory about 10 predictable periods when babies go through developmental leaps. During these leaps, babies may become more fussy, clingy, and have sleep disturbances as they learn new skills.

This calculator helps you track when your baby might experience these developmental leaps based on their birth date or due date.

Baby development
Understanding leaps
Understanding Leaps

Developmental leaps are periods when your baby's brain suddenly makes new connections, allowing them to perceive and understand the world in new ways.

Signs of a leap
Signs of a Leap

During leaps, babies often become more fussy, clingy, and may have trouble sleeping. These behaviors are signs that your baby is working hard on developing new skills.

Supporting development
Supporting Development

Each leap presents an opportunity to support your baby's development with appropriate activities, games, and interactions that help them master new skills.