BMI Calculator

What is BMI?

Body Mass Index (BMI) is a widely used screening tool that estimates body fat based on your weight and height. Developed by Belgian mathematician Adolphe Quetelet in the 1830s, BMI provides a quick snapshot of whether your weight falls within a healthy range relative to your stature.

While BMI doesn't directly measure body fat percentage, it correlates strongly with more precise methods like underwater weighing and dual-energy x-ray absorptiometry (DXA).

BMI Categories

The World Health Organization (WHO) classifies BMI into the following categories:

• Underweight: BMI below 18.5 — May indicate malnutrition or other health conditions requiring medical attention.
• Normal weight: BMI 18.5 to 24.9 — Associated with the lowest health risks for most adults.
• Overweight: BMI 25 to 29.9 — May indicate excess body weight that could increase cardiovascular disease risk.
• Obese: BMI 30 and above — Significantly elevated health risks requiring medical monitoring.

How to Use This Calculator

Enter your height in centimeters and weight in kilograms, then click "Calculate BMI." The tool instantly computes your BMI using the standard formula: BMI = weight(kg) / height(m)². You'll receive your numerical BMI value, health category classification, and guidance on healthy weight ranges.

Limitations of BMI

While useful, BMI has recognized limitations:

• Does not distinguish between muscle and fat mass
• May underestimate body fat in older adults who have lost muscle
• Does not account for fat distribution (visceral vs. subcutaneous)
• Not suitable for pregnant women, children, or very muscular individuals