General medicine

Body Mass Index (BMI)

Educational content onlySource-checked

Cross-checked against published sources on October 8, 2026 (automated, AI-assisted); not reviewed by a licensed clinician. Not medical advice, not for diagnosis or treatment decisions. Always verify with current guidelines and consult a qualified professional. We may be wrong: this page can contain errors. If you spot one, report it and we will check it against current sources and correct it.

Sources checked (4)

Centers for Disease Control and Prevention. Adult BMI Categories (accessed October 8, 2026)
National Heart, Lung, and Blood Institute (NIH). Calculate Your Body Mass Index (accessed October 8, 2026)
World Health Organization. Body mass index (Global Health Observatory) (accessed October 8, 2026)
Hindawi (Journal of Obesity), open access via Europe PMC. For Researchers on Obesity: Historical Review of Extra Body Weight Definitions (Table 4, WHO TRS 894 classification) (accessed October 8, 2026)

Source policy Medical disclaimer

Formula

BMI = weight (kg) / height (m)^2. WHO adult categories at 16, 17, 18.5, 25, 30, 35, 40 kg/m2.

Limitations

Adults only (WHO adult cut-offs); children require age- and sex-specific growth references.
Does not distinguish fat from lean mass; some populations (for example Asian populations) use different public-health cut-offs.

References

Obesity: preventing and managing the global epidemic. Report of a WHO consultation. World Health Organization. WHO Technical Report Series 894. Geneva: WHO; 2000. ISBN 9241208945.