Health WHO Standard

BMI Calculator

Calculate your Body Mass Index (BMI) using WHO guidelines. Enter your height and weight in metric or imperial units to get your BMI, category and healthy weight range.

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Weight

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Enter your height and weight

BMI is calculated as weight (kg) divided by height (m) squared.

BMI Categories (WHO International Standard)

BMI Range	Category	Health Risk	Action
Below 16.0	Severe Underweight	Very high risk	Medical attention recommended
16.0 to 17.0	Moderate Underweight	High risk	Consult a doctor
17.0 to 18.5	Mild Underweight	Raised risk	Dietary review advised
18.5 to 24.9	Normal Weight	Lowest risk	Maintain with diet and exercise
25.0 to 29.9	Overweight	Increased risk	Dietary changes and exercise
30.0 to 34.9	Obese Class I	High risk	Medical supervision recommended
35.0 to 39.9	Obese Class II	Very high risk	Medical treatment required
40.0 and above	Obese Class III	Extremely high risk	Urgent medical intervention

BMI Formula and Limitations

BMI = weight (kg) / height (m)²

Imperial: BMI = (weight in lbs × 703) / height (in)²

BMI is a screening tool, not a diagnostic measure. It does not account for muscle mass, bone density, fat distribution or sex differences. Highly muscular individuals (athletes) often have a high BMI despite low body fat. For a complete assessment, use BMI alongside waist circumference, body fat percentage and other clinical measures.

Asian populations: The WHO proposes lower cutoff points for Asian populations (overweight: BMI 23+, obese: BMI 27.5+) due to higher health risks at lower BMIs compared to European populations.