BMI Calculator for Children
BMI for children and teens (ages 2–19) is interpreted with CDC age- and sex-specific percentile charts rather than fixed adult cut-offs. This page explains how to read the result.
Variation of BMI Calculator
Results update automatically as you type.
How to Use
- Choose Metric or Imperial units.
- Select your gender and enter your age.
- Enter your height and weight.
- Read your BMI, category, and healthy weight range instantly.
Calculation Method
BMI is your weight divided by the square of your height.
- Metric: BMI = weight (kg) / [height (m)]²
- Imperial: BMI = 703 × weight (lb) / [height (in)]²
Categories: Underweight < 18.5 · Normal 18.5–24.9 · Overweight 25–29.9 · Obese ≥ 30.
Source: World Health Organization (WHO) BMI classification
Frequently Asked Questions
Children grow, so BMI naturally changes with age and sex. CDC percentiles compare a child to peers of the same age and sex.
Generally, a BMI between the 5th and 85th percentile for age and sex is considered healthy. Below 5th = underweight; 85th–95th = overweight; above 95th = obese.
Other Variations
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Health & Fitness Disclaimer
The health and fitness calculations provided are estimates only and should not replace professional medical advice. Consult with a healthcare provider, registered dietitian, or certified fitness professional before making significant changes to your diet or exercise routine.
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Last updated: May 24, 2026