BMI Calculator for Children

This is a free online calculator to calculate BMI of children/ adolescents aged 19 years or under. BMI-for-age is calculated in the same way as for adults, but the result is interpreted in terms of age- and sex-specific percentiles (Reference: WHO growth chart for boys/ girls). For adults, on the other hand, BMI values are independent of sex or age.

Height & weight values may be entered either in metric or imperial units.

Metric Imperial
Height: cm
Weight: Kg
Height: ft in
Weight: lb
Date of Birth:

If the child is less than 2 years, measure the length of the body lying down for height value.

The following table lists the nutritional status corresponding to the weight percentile of children using BMI-for-age calculation.

CategoryPercentile Range
UnderweightLess than the 5th percentile
Healthy weight5th percentile to less than the 85th percentile
Overweight85th to less than the 95th percentile
ObeseEqual to or greater than the 95th percentile