BMI Calculator

What is BMI?

Body Mass Index (BMI) is a simple measure that uses your height and weight to estimate whether you are underweight, normal weight, overweight, or obese. It was developed by Belgian mathematician Adolphe Quetelet in the 1830s and remains one of the most widely used screening tools for weight-related health risks.

The formula for BMI is weight in kilograms divided by height in meters squared (kg/m²). For imperial units, multiply the result by 703. A BMI between 18.5 and 24.9 is generally considered normal weight. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is classified as obese. These categories are used by the World Health Organization (WHO) and healthcare providers worldwide as a quick screening tool.

Limitations of BMI

While BMI is a useful screening tool, it has significant limitations. It does not distinguish between muscle mass and fat mass, so athletes or individuals with high muscle mass may be classified as overweight or obese despite having low body fat. Similarly, BMI may underestimate body fat in older adults who have lost muscle mass.

BMI also does not account for fat distribution, which is an important health indicator. Visceral fat (around the waist) is associated with higher health risks than subcutaneous fat (under the skin). For a more complete assessment, BMI should be used alongside other measurements such as waist circumference, body fat percentage, or waist-to-hip ratio. Always consult a healthcare professional for a comprehensive health evaluation.