BMI Calculator

The BMI Calculator computes your Body Mass Index — a screening metric that relates your weight to your height. BMI is widely used by health organizations including the World Health Organization (WHO) and the Centers for Disease Control (CDC) as a quick population-level indicator of whether a person's weight is in a healthy range for their height.

BMI is calculated as weight (kg) divided by height (m) squared. In imperial units it is weight (lb) times 703 divided by height (in) squared. The result is a single number that falls into one of four WHO categories: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25–29.9), or Obese (30 and above). This calculator shows your BMI, your category, and the healthy weight range for your specific height — the weight interval that would put you in the Normal range.

It is important to understand what BMI can and cannot tell you. BMI is a useful screening tool at a population level, but it does not directly measure body fat or health. Muscular athletes often score 'Overweight' because muscle is denser than fat; older adults may have a 'Normal' BMI but high body-fat percentage; and BMI says nothing about fat distribution, which matters for cardiovascular risk. Use BMI as one signal among many — alongside waist circumference, blood pressure, and how you feel — and discuss any concerns with a qualified healthcare professional.

The calculator supports both metric (kilograms, centimeters) and imperial (pounds, feet/inches) units and switches instantly between them. Everything runs locally; your measurements are not stored or transmitted.