How to Determine Body Fat Index

The Body Mass Index, or BMI, is an indicator of body fat percentage by weight and height. The index is in an inexpensive method to determine if your body fat puts you a risk for certain diseases. A body fat percentage of less than 18.5 percent is considered underweight, while 18.5 to 24.9 is normal. A percentage of 25 to 29.9 percent is considered overweight and a percentage of 30 or greater is considered obese. While the index works for most people, it may overestimate the percentage of body in those with muscular builds and underestimate in those who have lost muscle, such as the elderly.

Instructions

• 1

  Access the body mass index calculator on the National Heart Lung and Blood Institute website. Select the "Standard" or "Metric" tab.

• 2

  Locate the field labeled "Your Height." Enter your height in feet and inches if using the standard setting or centimeters if using the metric setting.

• 3

  Locate the field labeled "Your Weight." Enter your weight in pounds if using the standard setting or kilograms if using the metric setting.

• 4

  Select "Compute BMI" to determine your percentage of body fat. Your percentage will appear in the box labeled "Your BMI." Take note of your percentage. Compare your percentage to the ranges provided to determine whether you are of a normal weight, or underweight, overweight or obese.