Body Mass Index (BMI) Calculator
Quickly calculate your BMI and determine your weight category.
What is Body Mass Index (BMI)?
Body Mass Index (BMI) is a simple numerical measurement used to categorize a person as underweight, healthy weight, overweight, or obese. It is calculated by dividing a person's weight in kilograms by the square of their height in meters.
BMI is a screening tool used by healthcare professionals to identify potential weight problems in adults. While BMI does not measure body fat directly, research has shown that BMI is moderately correlated with more direct measures of body fat.
BMI Classification Table
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy Weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and Above | Obese |
How the Calculation Works
Depending on which system of measurement you use, the formula varies slightly:
- Metric: Weight (kg) / [Height (m)]²
- Imperial: 703 × Weight (lbs) / [Height (in)]²
Example Calculation
If an adult male is 180 cm tall and weighs 80 kg, the calculation would be:
- Convert height to meters: 180 cm = 1.8 meters
- Square the height: 1.8 × 1.8 = 3.24
- Divide weight by squared height: 80 / 3.24 = 24.69 BMI
- Result: This individual falls within the "Healthy Weight" category.
Why BMI Matters
Maintaining a healthy BMI is associated with a lower risk of chronic conditions such as Type 2 diabetes, cardiovascular disease, and certain types of cancer. However, it's important to note that BMI is a general indicator and does not account for muscle mass, bone density, or overall body composition. For example, athletes often have a high BMI due to muscle mass rather than excess body fat.