BMI Calculator

Maintaining a healthy weight is crucial for reducing the risk of conditions like heart disease, diabetes, and high blood pressure. Our BMI Calculator uses the official World Health Organization (WHO) formulas to instantly categorize your weight and provide you with a personalized target weight range for your specific height.

Body Mass Index is a simple ratio of your weight to your height. In metric units, the formula is weight in kilograms divided by height in meters squared (kg/m²). For example, someone who is 1.75 m tall and weighs 70 kg has a BMI of 70 ÷ (1.75 × 1.75) = about 22.9, which sits comfortably in the healthy range. The imperial version multiplies the result by a conversion factor: weight in pounds divided by height in inches squared, times 703. You do not need to do any of this by hand — enter your height and weight above in whichever units you prefer and the calculator handles the math instantly, then shows which category the result falls into.

BMI is popular because it is quick, free, and requires nothing but a height and weight. But it is a rough screening tool, not a complete picture of health. Its biggest blind spot is that it cannot tell muscle from fat — a very fit athlete with heavy muscle can register as "overweight" despite low body fat, while someone with little muscle might have a "normal" BMI yet carry excess fat. It also does not account for where fat is stored, age, sex, or ethnicity, all of which affect health risk. Because of this, doctors use BMI alongside other measures like waist circumference and blood tests rather than on its own. Treat your result here as a helpful starting point for a conversation, not a verdict. This tool is for general information only and is not a substitute for professional medical advice — for any health concern, please speak with a qualified healthcare provider.