Free BMI Calculator

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REFERENCE_GUIDE

< 18.5UNDERWEIGHT

Possible nutrient deficiency or underlying health issues.

18.5 – 25HEALTHY

Ideal balance of weight relative to height. Lower risk of disease.

25.0 – 30OVERWEIGHT

Increased risk for cardiovascular stress and metabolic issues.

≥ 30.0OBESE

Significant risk for type 2 diabetes, hypertension, and heart disease.

THE FORMULA

BMI is calculated as kg/m2. It provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.

LIMITATIONS

While useful for populations, it does not account for age, sex, bone structure, or fat distribution (visceral vs. subcutaneous), which are all critical markers of metabolic health.

IMPORTANT_ADVISORY: MUSCLE_DENSITY

BMI is a generalized screening tool and does not directly measure body fat percentage. For individuals with high muscle density(athletes, bodybuilders), the scale often fails. Because muscle is roughly 18% denser than fat, highly fit individuals may be categorized as "Overweight" or "Obese" despite having athletic levels of body fat.

OFFICIAL SOURCEWorld Health Organization (WHO) Global DatabaseREF: 2026_METRIC_STANDARD