BMI Calculator
Enter your height and weight to calculate your BMI. Toggle between metric and imperial units. Results include the WHO category and a visual scale.
BMI is a population-level screening heuristic based on height and weight alone. It does not account for muscle mass, bone density, age, sex, or ethnicity, and should not be used as an individual diagnostic measure.
This calculator provides estimates based on population-level formulas and is not a substitute for advice from a qualified health professional.
How it works
Body Mass Index is calculated by dividing your weight in kilograms by the square of your height in metres (kg/m²). When you use imperial units, the tool first converts pounds to kilograms and inches to metres before applying the same formula. The resulting number is then compared against the World Health Organization classification ranges: underweight (below 18.5), normal weight (18.5–24.9), overweight (25–29.9), and obese (30 and above).
BMI is a quick screening tool, not a diagnostic measure. It does not distinguish between muscle and fat mass, so athletes with high muscle density may register as overweight despite having a healthy body composition. Likewise, age, sex, and ethnicity can influence what constitutes a healthy range. For a complete picture of your health, consult a healthcare professional.
The visual scale shown alongside your result gives you an at-a-glance sense of where your BMI falls relative to the WHO categories. All calculations are performed locally in your browser and no personal data is stored or transmitted.