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Calculate Body Mass Index (BMI) from height and weight in kilograms/centimeters or pounds/feet-inches. See standard adult category bands used in public health screening (WHO-style thresholds, often cited alongside CDC guidance) and read why BMI is only one screening signal—not a diagnosis.
BMI Calculator (Adult) computes Body Mass Index from height and weight, shows standard adult WHO-style category bands, and explains limits so results are easier to interpret responsibly.
BMI is computed as weight (kg) divided by height (m) squared, with US inputs converted using standard inch/meter and pound/kilogram factors. Adult categories use WHO screening thresholds commonly referenced with CDC educational materials; this is not a clinical instrument.
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BMI is weight in kilograms divided by height in meters squared (kg/m²). With US units, an equivalent formula is 703 × weight in pounds ÷ height in inches squared.
Adult categories follow widely used WHO thresholds: underweight below 18.5, normal 18.5 up to 25, overweight 25 up to 30, and obesity classes from 30 upward. Public agencies like CDC reference similar bands for screening education.
No. This calculator is for general education only. It does not diagnose disease or replace a clinician. Always seek professional guidance for health decisions.
No server-side storage is required for the calculation. Values may appear in your browser URL if you use the shareable link feature—avoid sharing if you want to keep inputs private.
BMI does not measure body fat directly. Very muscular people can have a higher BMI with low body fat. Older adults, some chronic illnesses, and different ethnic backgrounds can change how BMI relates to health risk—clinical context matters.
Children and teens require age- and sex-specific growth charts (percentiles), not the simple adult thresholds shown here. Use pediatric guidance from a healthcare provider.
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