BMI (Body Mass Index)


The body mass index (BMI), or Quetelet index, is a measure for human body shape based on an individual’s mass and height. It is defined as the individual’s body mass divided by the square of their height – with the value universally being given in units of kg/m2.

BMI is a fairly reliable indicator of body fatness for most people. BMI does not measure body fat directly, but research has shown that BMI correlates to direct measures of body fat. Additionally, BMI is an inexpensive and easy-to-perform method of screening for weight categories that may lead to health problems.

A BMI of 18.5 to 25 may indicate optimal weight, a BMI lower than 18.5 suggests the person is underweight, a number above 25 may indicate the person is overweight, a number above 30 suggests the person is obese.

BMI can also be determined using a table or from a chart which displays BMI as a function of mass and height using contour lines, or colors for different BMI categories.