BMI Calculator
Calculate your Body Mass Index from height and weight.
Measurements
ft in
lbs
How It Works
Body Mass Index (BMI) is calculated as weight in kilograms divided by height in meters
squared (kg/m²). For imperial units, the formula is (lbs / inches²) × 703. The WHO defines four categories: Underweight (<
18.5), Normal (18.5–24.9), Overweight (25–29.9), and Obese (≥ 30).
BMI is a useful screening tool but has well-known limitations — it doesn't distinguish between muscle and fat mass, varies by age and ethnicity, and can misclassify athletes as overweight. Consult a healthcare provider for a full health assessment.