Check if a child's height and weight are within WHO ranges.
For under 1 year, use decimals (e.g. 0.5 for 6 months)
Fill in the form and click "Compute centiles" to see results.
Below 3rd centile - consult a pediatrician.
Between 3rd and 15th centile - may need attention.
Between 15th and 85th centile - within typical range.
Between 85th and 97th centile - may need attention.
Above 97th centile - consult a pediatrician.
Centile charts visualize the distribution of physical traits (height, weight, BMI) in a reference population by age and sex.
Centile indicates the position relative to peers (e.g. 75th centile: 75% lower, 25% higher).
WHO uses the LMS method (Lambda-Mu-Sigma) with three parameters to model distributions:
Z-score formulas:
For L ≠ 0: Z = ((X/M)^L - 1) / (L × S)
For L = 0: Z = log(X/M) / S
Z-score is then converted to a centile using the normal distribution CDF.