Adult BMI calculator
Calculate body mass index from one height and weight reading in metric or imperial units. The result is a population screening band, not a personal health verdict.
Not for diagnosis. BMI cannot diagnose obesity, fitness, nutrition or health. This adult calculator is not appropriate for people under 20, pregnancy, or clinical situations where weight or body composition is altered. A qualified professional can interpret it alongside history, examination and other measures.
Result
Confirm adult applicability and enter measurements to see the calculation and screening band.
What the bands mean—and do not mean
WHO adult population bands are below 18.5, 18.5–24.9, 25–29.9 and 30 or above. This app labels them as screening bands and avoids diagnosis language. People with the same BMI can have different body composition and health. For better measurement-quality context, use the distinct BMI Measurement Quality Worksheet.
Official sources, reviewed 26 July 2026: CDC Adult BMI Calculator (26 June 2024); WHO obesity and overweight fact sheet.