Child & Teen BMI Calculator
This child BMI calculator helps estimate BMI-for-age percentile for children and teens aged 2 to 19 using CDC growth chart reference data with sex- and age-specific interpretation.
This tool is part of our broader calculator collection. You may also find our adult BMI calculator and health calculators hub useful.
Child’s Details
Results
Assumptions & Limitations
Body mass index-for-age percentiles: Boys, 2 to 19 years
📋 Calculation Breakdown
| Item | Value |
|---|---|
| Enter details to see the breakdown. | |
📚 CDC BMI-for-Age Categories
| Category | Rule | Meaning |
|---|---|---|
| Underweight | < 5th percentile | Below the healthy weight range for age and sex |
| Healthy weight | 5th to < 85th percentile | Healthy weight range for age and sex |
| Overweight | 85th to < 95th percentile | Above the healthy weight range for age and sex |
| Obesity | ≥ 95th percentile | Significantly above the healthy range for age and sex |
| Severe Obesity | ≥ 120% of the 95th percentile OR BMI ≥ 35 kg/m² | Highest risk category (subset of obesity). Medical guidance is strongly recommended. |
Child BMI Calculator FAQs
General guidance about child BMI. Consult a healthcare professional for personalized advice.
Q1: What age range does this calculator cover?
A: This calculator covers children and teens aged 2 to 19 years. For infants under 2, different growth standards are used. For adults 20 and older, use the adult BMI calculator.
Q2: Why does child BMI use percentiles instead of fixed categories?
A: Because children’s body composition changes as they grow. A healthy BMI for a 5-year-old is different from a healthy BMI for a 15-year-old. Percentiles compare the child’s BMI to a reference population of children of the same age and sex.
Q3: What growth reference does this calculator use?
A: This calculator uses the CDC (Centers for Disease Control and Prevention) BMI-for-age growth chart reference data from the year 2000 revised growth charts. This is the standard used in the United States.
Q4: Is this calculator accurate for children outside the United States?
A: The CDC growth reference is widely used internationally for screening purposes. However, some countries use WHO growth standards or their own national references. For country-specific guidance, consult a local pediatrician.
Q5: My child’s BMI percentile seems high. Should I be worried?
A: A single BMI measurement is a screening tool, not a diagnosis. Many factors affect a child’s weight, including growth spurts, puberty, muscle mass, and genetics. Consult your child’s doctor for a proper assessment.
Q6: How often should I check my child’s BMI?
A: Pediatricians typically measure BMI at annual well-child visits. Tracking BMI over time is more meaningful than a single measurement. Focus on overall health habits rather than frequent weighing.
Q7: Why Is Child BMI Different from Adult BMI?
A: For adults, BMI is interpreted using fixed cutoffs (18.5, 25, 30). For children and teens, BMI changes naturally as they grow. A BMI of 18 might be healthy for a 10-year-old
Sources & Further Reading
This calculator uses CDC BMI-for-age growth chart reference data.