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BMI Calculator

Calculate your Body Mass Index instantly. Get your BMI value and WHO health classification.

About This BMI Calculator

Body Mass Index (BMI) is a screening tool that estimates body fat based on height and weight. It's calculated by dividing weight in kg by height in meters squared. While not a perfect health metric, it's a useful starting point for understanding weight-related health risks.

Limitations: BMI doesn't account for muscle mass, bone density, or fat distribution. Athletes and older adults should use it as a rough guide, not a diagnosis.

BMI Categories (WHO Standard)

< 18.5
Underweight
18.5–24.9
Normal
25–29.9
Overweight
≥ 30
Obese

How to Use

  1. Select your preferred unit system (metric or imperial)
  2. Enter your weight and height
  3. Click Calculate to see your BMI value and category

Frequently Asked Questions

What is BMI?

Body Mass Index (BMI) is a screening tool that estimates body fat based on height and weight. It's calculated as weight (kg) divided by height squared (m²).

Is BMI accurate for athletes?

BMI may overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Use it as a general guide.

What's a healthy BMI?

A BMI between 18.5 and 24.9 is considered the healthy range by WHO standards. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is obese.

Is my data stored or sent anywhere?

No. All calculations happen entirely in your browser. Nothing is sent to any server.