BMI Calculator
Calculate your Body Mass Index using your weight in kilograms and height in centimeters. View your BMI and a general adult BMI category instantly.
What Is Body Mass Index (BMI)?
Body Mass Index, or BMI, is a number calculated from a person's weight and height. It is commonly used as a screening measure to group adult weight relative to height. BMI does not directly measure body fat and cannot determine a person's overall health on its own.
BMI Formula
To calculate BMI using metric measurements, divide weight in kilograms by height in meters squared.
BMI = Weight (kg) ÷ [Height (m) × Height (m)]
Example: A person weighing 70 kg and measuring 175 cm tall has a BMI of approximately 22.9.
Adult BMI Categories
The following are commonly used BMI categories for adults. These ranges are general screening guidelines.
| BMI Range | Adult Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Healthy weight range |
| 25.0 to 29.9 | Overweight |
| 30.0 or above | Obesity range |
How to Use This BMI Calculator
- Enter your weight in kilograms.
- Enter your height in centimeters.
- Select Calculate BMI.
- Review your BMI result and its general adult category.
Why Can BMI Be Limited?
BMI does not distinguish muscle from fat or show where body fat is distributed. Age, muscle mass, pregnancy and other individual factors may affect how a BMI result should be interpreted. Children and teenagers require age- and sex-specific BMI assessment rather than standard adult categories.
Frequently Asked Questions
What is a healthy BMI for adults?
A BMI from 18.5 to 24.9 is commonly classified as the healthy-weight range for adults. This is a screening range, not a guarantee of good health.
How is BMI calculated from height and weight?
Convert height in centimeters to meters, multiply the height by itself, and divide weight in kilograms by that result. For example, 70 ÷ (1.75 × 1.75) is approximately 22.9.
Is BMI the same as body fat percentage?
No. BMI uses height and weight, while body fat percentage estimates the proportion of the body made up of fat. They measure different things.
Can this calculator be used for children?
This calculator displays standard adult BMI categories. Children and teenagers need a different interpretation based on age and sex. Ask a qualified healthcare professional for appropriate guidance.
Is this BMI calculator free?
Yes. You can use this BMI calculator for free in your web browser without installing an application.
Learn More About BMI
For more details about BMI calculations, examples and adult categories, read our guide: How to Calculate BMI: Formula, Categories & Examples .
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