BMI, or Body Mass Index, is a numerical value derived from an individual’s weight and height. It is defined as the individual’s body mass divided by the square of their height. The formula for calculating BMI is: BMI = weight (kg) / [height (m)]^2 To calculate BMI using pounds (lbs) and inches (in), the formula is BMI = [weight (lbs) / [height (in)]^2] * 703 The “703” in the second formula is to convert the index from the original metric version of the formula to the English (Imperial) version. BMI is commonly used to quickly and simply identify whether a person has a healthy body weight for a given height. It is used to screen for weight categories that may lead to health problems. Here’s a general guide to what the BMI values mean Underweight: a BMI less than 18.5. Normal weight: a BMI of 18.5–24.9. Overweight: a BMI of 25–29.9. Obesity: a BMI of 30 or more. While BMI can be a useful tool for identifying those who are underweight, normal weight, overweight, or obese, it is not a diagnostic tool. It does not account for factors like muscle mass, bone density, overall body composition, and racial and sex differences. Hence, it’s important to consider other factors and tests when evaluating one’s overall health and fitness.