Not by itself. BMI is a screening tool; diagnosis and treatment decisions require clinical assessment, history, exams and other indicators.
BMI Calculator
Calculate adult BMI with classification, a visual scale and clear limitations.
Adult BMI with context, not alarmism.
Body Mass Index is a ratio between weight and height used as a screening tool in adults. It is fast and useful at population level, but it does not directly measure body fat and can mislead for athletes, older adults, pregnancy, very muscular people or specific medical conditions.
Enter three values and read the result carefully.
- Enter adult age, height and weight in metric or imperial units.
- Check the rounded BMI, matching range and visual scale.
- Use the result as educational screening, not as a medical decision or prescription.
What BMI does and does not measure
BMI measures a mathematical relationship between mass and height. It does not separate muscle, fat, bone, fluid retention or fat distribution.
Safe interpretation combines the number with history, waist, body composition, symptoms, lab work and professional assessment when health decisions are involved.
- Adults: use this page for ages 20+.
- Children and teens: use BMI-for-age percentiles.
- Pregnancy, edema, amputations and high muscle mass need individualized interpretation.