Body Mass Index (BMI) is a medical screening tool that estimates a person's body fat based on their height and weight ratio. It is used to identify potential weight-related health risks.

BMI Formula

The metric formula is:

BMI = \frac{weight\text{ (kg)}}{height^{2}\text{ (m^{2})}}

For imperial calculations, the formula incorporates a scaling factor:

BMI = \frac{weight\text{ (lbs)}}{height^{2}\text{ (inches)}} \times 703

Classification Categories

World Health Organization (WHO) outlines standard weight classifications:

  • Underweight: BMI below 18.5
  • Normal Weight: BMI between 18.5 and 24.9
  • Overweight: BMI between 25.0 and 29.9
  • Obese: BMI of 30.0 or higher

Use these metrics as a screening guideline, not as a direct diagnostic tool.