BMI calculator for kids and teens
Children’s BMI must be interpreted by age and sex using growth-chart percentiles. Use the CDC’s calculator below for children and teens ages 2 through 19.
Searching for an AI bmi calculator for kids and teens? This one uses a standard published formula, not an AI model, so you can see exactly how your number is made. See how BiteCal AI tracks meals against it.
Official CDC tool
BMI-for-age calculator · Ages 2–19
If the calculator does not load, open the CDC Child and Teen BMI Calculator directly.
Your result explained
The official CDC calculator reports BMI, BMI-for-age percentile, category, and a growth-chart plot. This page embeds that tool directly; it does not estimate a child’s percentile from adult BMI cutoffs.
How it’s calculated
BMI is calculated from weight and height, then interpreted against CDC BMI-for-age reference curves using age- and sex-specific values. The CDC calculator handles those reference data and growth-chart details.
Worked example: A child’s percentile cannot be inferred from BMI alone. The CDC tool requires the age, sex, height, and weight inputs used by its growth-chart calculation.
Limits and accuracy
This embedded tool is provided by the CDC and is limited to ages 2 through 19. It is a screening aid, not medical advice. Children under 2 need a different growth assessment; for other populations or clinical questions, consult a qualified healthcare professional.
Frequently asked questions
Why is children’s BMI different from adult BMI?
Children’s BMI is interpreted by age- and sex-specific percentiles because growth and body composition change during development. Adult fixed category cutoffs do not apply.
What ages does the CDC child BMI calculator cover?
The CDC child and teen BMI calculator covers ages 2 through 19. For younger children, use guidance from a pediatric healthcare professional.
Does the percentile diagnose a health condition?
No. BMI-for-age is a screening measure and should be considered with a child’s growth history and other clinical information.
What measurements should I prepare?
The CDC tool asks for the child's sex, age, height, and weight. Measure height and weight carefully and use the same units shown in the form.
Should a parent use this percentile to plan weight loss?
No. Do not use a percentile to set a child’s calorie restriction or weight-loss plan. Discuss growth and nutrition with a pediatric clinician.
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Estimates only. This is not medical advice. Last reviewed: 20 October 2026.