Baby Growth Calculator

Track and compare your baby growth percentiles

Based on WHO Child Growth Standards (weight-for-age), birth to 24 months.

Every baby grows at their own pace, but comparing your baby's weight to standardized growth data can offer helpful context. Our baby growth calculator estimates your baby's weight percentile using the World Health Organization's Child Growth Standards.

Whether you're tracking growth between pediatrician visits or simply curious how your baby compares to global averages, this tool gives you a quick, easy-to-understand percentile estimate.

How This Calculator Works

Enter your baby's gender, age in months (0–24), and current weight in kilograms. The calculator compares this against WHO's weight-for-age growth charts to estimate a percentile — for example, the 50th percentile means your baby's weight matches the median for babies of that age and gender, while higher or lower percentiles show where your baby falls relative to that median.

Why Use This Calculator

  • Quick percentile estimate based on internationally recognized WHO standards
  • Separate calculations for boys and girls, since growth patterns differ
  • Useful reference between pediatrician checkups
  • Simple, jargon-free explanation of where your baby's weight falls

Frequently Asked Questions

A percentile shows how your baby's weight compares to other babies of the same age and gender. For instance, a baby in the 60th percentile weighs more than 60% of babies their age, and less than 40%.

Not necessarily. Babies grow at different rates, and what matters most is a steady growth trend over time rather than a single percentile number. Sudden drops across percentile lines are more worth discussing with your pediatrician.

No, this tool is meant as a helpful reference, not a replacement for the official growth tracking your pediatrician maintains using your baby's full history.

This calculator uses standard WHO charts, which may not fully account for prematurity. For preemies, ask your pediatrician about corrected-age growth charts.
This tool is for general informational purposes only and is not a clinical diagnosis. Always consult your pediatrician about your baby's growth and development.
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