Body Mass Index (BMI) Calculator
Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in meters (kg/m²).
This professional calculator allows you to compute your BMI using standard Metric or Imperial units. It also provides a visual risk gauge and estimates your ideal weight range based on clinical guidelines.
Metric Units
KG / CMStandard international units used in clinical settings.
Imperial Units
LBS / INCommonly used units in the United States.
Clinical Context
According to the World Health Organization (WHO), for adults over 20 years old, BMI falls into the following categories:
- Underweight: Below 18.5 kg/m²
- Normal weight: 18.5 – 24.9 kg/m²
- Overweight: 25.0 – 29.9 kg/m²
- Obesity: 30.0 kg/m² and above
Clinical References
How to Use This Calculator
Enter Measurements
You can use either the Metric side (left) or Imperial side (right). The system will automatically convert for you.
Calculate
Click Calculate BMI. The tool will calculate your score, categorize it, and calculate your optimal weight range.