Medically reviewed by Suzanne Fisher, RD Key Takeaways Body mass index (BMI) is a calculation used to estimate your body fat.

BMI, also referred to as Body Mass Index, is a method used in screening one’s body fat. This is done by measuring the height and weight of a person and converting it into their equivalent BMI.

Using a body mass index (BMI) calculator can help a person determine whether their weight is within the recommended range for their height. However, BMI calculations have several important limitations ...

BMI is an estimate of body composition based on weight and height. For people of any sex, a moderate BMI is usually 18.5 to 24.9. For people assigned female at birth, BMI does have some limitations.