Baby Growth Percentile
Enter your baby's age, sex, weight, length, and head circumference to instantly see growth percentiles based on WHO reference data.
Use the Baby Growth Percentile
Baby Details
Use completed whole months; this tool does not interpolate fractional ages.
Fill in the details on the left and click Calculate Percentiles.
Growth Percentile Results
How to Interpret These Results
These percentiles are screening references, not diagnoses. Meaning differs for weight-for-age, length-for-age, and head circumference-for-age; weight-for-age alone does not diagnose overweight. Review accurate serial measurements with a qualified pediatric clinician.
Summary
The Baby Growth Percentile Calculator uses WHO Child Growth Standards (2006) to assess your infant's weight, length, and head circumference relative to a global reference population of the same age and sex. It applies the LMS (Lambda-Mu-Sigma) statistical method — the same technique used in official WHO growth charts — to convert raw measurements into accurate percentile scores. The tool covers boys and girls from birth through 24 months and works in both metric and imperial units.
How it works
- Select your baby's sex (boy or girl).
- Enter the baby's age in whole months (0–24).
- Enter the baby's weight in kilograms or pounds.
- Enter the baby's length in centimeters or inches.
- Optionally enter head circumference to get that percentile too.
- Click "Calculate" to see all percentiles on the WHO growth chart.
Use cases
- Track your infant's growth between pediatric check-ups.
- Understand whether your baby's weight is on track for their age and sex.
- Monitor head circumference development in the first two years.
- Compare growth measurements against WHO international standards.
- Prepare questions for your pediatrician with accurate percentile data.
- Spot potential growth concerns early by tracking trends over time.