Baby Growth Percentile Calculator
Compare your baby's weight and length to WHO growth charts. See what percentile your baby falls in for age and gender.
Results
Visualization
How It Works
Growth percentiles show how your baby compares to other babies of the same age and gender using WHO growth charts. A 50th percentile means average. What matters most is consistent growth along a curve, not the specific number. Not medical advice -- your pediatrician tracks growth over time.
The Formula
Z-score = (Measurement - Median) / Standard Deviation
Percentile derived from z-score using normal distribution
Based on WHO Child Growth Standards (0-24 months)
Percentile derived from z-score using normal distribution
Based on WHO Child Growth Standards (0-24 months)
Variables
- Percentile — Percentage of children who are smaller (e.g., 75th = bigger than 75% of peers)
- WHO median — The 50th percentile value from World Health Organization growth charts
Example
6-month-old girl at 16 lbs and 26 inches is approximately 50th percentile for both -- right at average.
Tips
- Consistent growth along ANY percentile curve is healthy -- 10th is as good as 90th
- Crossing two or more percentile lines (up or down) may need investigation
- Premature babies should use adjusted age for growth charts
- Breastfed babies may grow differently than formula-fed babies in the first year
- Growth spurts can cause temporary jumps in percentile