📈 BMI Percentile Calculator
Estimate where a child or teen’s BMI falls compared to others of the same age and sex, based on standard growth chart patterns.
What is a BMI percentile
Unlike adults, children and teens are compared to others of the same age and sex, because a healthy BMI naturally changes as kids grow. A BMI percentile shows where a child’s BMI ranks against that reference group — for example, a value at the 60th percentile means the child’s BMI is higher than about 60% of peers of the same age and sex.
How this calculator estimates it
This calculator first computes BMI from height and weight, then compares it to a smooth mathematical model of typical age- and sex-specific BMI patterns (the general shape used by official growth charts) to estimate a percentile. Standard screening bands are applied: below the 5th percentile is underweight, 5th–85th is a healthy weight, 85th–95th is overweight, and 95th and above is obese.
Note: this tool uses an approximation model rather than exact official growth chart lookup tables, so results are an estimate for general and educational use. For a clinically precise percentile, use an official CDC or WHO growth chart or ask a pediatrician.