BMI Calculator

Check your Body Mass Index with metric or imperial units. See your weight category and healthy weight range instantly.

BMI Calculator — Body Mass Index
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BMI categories (WHO)
CategoryBMI Range
Underweight< 18.5
Normal weight18.5 – 24.9
Overweight25 – 29.9
Obese I30 – 34.9
Obese II35 – 39.9
Obese III≥ 40

What is BMI?

Body Mass Index (BMI) is a simple measure of a person's weight relative to height. The WHO uses it as a screening tool to identify weight categories that may lead to health problems.

BMI formula

Metric: BMI = weight (kg) ÷ height² (m) · Example: 70 kg ÷ 1.75² = 22.9

Imperial: BMI = (weight (lbs) ÷ height² (inches)) × 703

Limitations of BMI

BMI does not directly measure body fat and can be misleading for athletes, elderly people, or those with high muscle mass. Always consult a healthcare professional for a full assessment.

Step-by-step guide How to Calculate Your BMI — Complete Guide →