BMI Calculator

Understanding Body Mass Index & Health Ranges

BMI estimates body fat from weight and height: metric BMI is weight in kilograms divided by height in meters squared, and the imperial formula multiplies pounds ÷ inches² by 703. The standard categories are underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30). The healthy weight range shown is the weight at which your BMI falls in the normal category for your height.

For Asian and South Asian populations, studies show that metabolic risk increases at lower BMIs, meaning an adjusted threshold of 23.0 for overweight and 27.5 for obesity is highly recommended. The Ponderal Index (Rohrer's Index) scales weight by the cube of height (kg/m³), correcting height bias in extremely short or tall users. All math is performed locally.