Adult BMI Calculator
Enter metric height and weight to calculate BMI as kilograms per square metre. The result shows the CDC category for adults age 20 or older and keeps the screening limitations visible.
Adult screening estimate only; not a diagnosis or medical advice. The CDC category table used here is for adults age 20 or older, not children or teens. Pregnancy, unusually high muscle mass, health history, and other factors require different context.
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Use the details that match your situation. Your estimate stays in this browser.
How this estimate works
- BMI equals weight in kilograms divided by height in metres squared.
- The result is rounded to one decimal place and mapped to the CDC adult categories: underweight, healthy weight, overweight, and obesity classes.
- BMI is only one potential health indicator and should be considered with history, behaviors, examination findings, and other measurements.
Official health sources
- CDC: adult BMI calculator, categories, and screening limitations
- World Health Organization: BMI formula and adult thresholds
CDC and WHO describe BMI as a screening or surrogate measure rather than a complete individual health assessment. Seek a qualified clinician for personal interpretation.
Frequently asked questions
Is BMI a diagnosis?
No. CDC describes BMI as a screening measure that should be considered with medical history, health behaviors, examinations, and other findings.
Can children use this adult BMI calculator?
No. Children and teens need age- and sex-specific BMI assessment. This category table is intended for adults age 20 or older.