How do I calculate BMI?

BMI = weight(kg) / height(m) squared. Imperial: 703 x weight(lbs) / height(inches) squared. A 70kg person at 170cm: 70 / 1.70^2 = 24.2 (normal weight). WHO categories: under 18.5 underweight, 18.5-24.9 normal, 25-29.9 overweight, 30+ obese.

BMI Calculator — Body Mass Index for Adults & Children

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Body Mass Index Calculator

Unit System

Weight (kg)

Height (cm)

Age

Sex

BMI Standard

Waist Circumference (optional) For waist-to-height ratio

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Underweight
<18.5Normal
18.5–24.9Overweight
25–29.9Obese I
30–34.9Obese II+
35+

Healthy Weight Range

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For your height

BMI Prime

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Ponderal Index

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kg/m³ — height-adjusted

Weight to Lose/Gain

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BMI Category

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BMI Classification Table

Category	BMI Range	Your Weight Range

⚠️ Note: BMI is a screening tool, not a diagnostic measure. It doesn't account for muscle mass, bone density, age, sex, or body composition. Athletes and muscular individuals may have a high BMI without excess body fat. Consult a healthcare professional for a complete health assessment.