Body Fat Percent Calculator

Body fat measurements and the measuring tape are recognized as superior methods for measuring "weight loss". When one declares that they want to "lose weight", what they often mean is that they want to lose fat. So, now that you've had your body fat measured, what does the number really mean?

First, your body fat percentage is simply the percentage of fat your body contains. If you are 150 pounds and 10% fat, it means that your body consists of 15 pounds fat and 135 pounds lean body mass (bone, muscle, organ tissue, blood and everything else).

A certain amount of fat is essential to bodily functions. Fat regulates body temperature, cushions and insulates organs and tissues and is the main form of the body's energy storage. The following table describes body fat ranges and their associated categories:

Knowing your body fat percentage can also help you determine if your weight loss goals are realistic. Remember, weight loss doesn't always mean fat loss. For example:

Let's say you're a 130 lbs. woman with 23% body fat, and you goal is to "lose 20 pounds":

Initial body fat: 130 lbs. x 0.23 fat = 30 lbs. body fat

Lean body mass: 130 lbs. total - 30 lbs. fat = 100 lbs. lean body mass (bones, organs and all else)

Goal: 130 lbs. - 20 lbs. = 110 pounds

As you can see, the goal of losing 20 pounds is not realistic or healthy. At 110 pounds, this woman still requires 100 pounds of lean body mass (bones, organs, etc.), but would only be carrying 10 pounds, or only 9% body fat. From the chart above, you can see that this is a dangerously low percentage.

A better goal might be for the woman to reduce her body fat from 23% to 18%. In this case:

130 lbs. x 0.18 = 23 lbs. body fat

100 lbs. lean body mass + 23 lbs. = 123 lbs. goal weight

So, for this individual to achieve a lean, but healthy 18% fat, she would need to lose only 7 pounds of fat, reducing her weight from her current 130 pounds to 123 pounds. Losing more than 7 pounds means losing lean body mass (usually metabolically-active muscle tissue), which is clearly not desirable.

So before you decide that you need to "lose weight", remember to consider that "weight" consists of both lean body mass and body fat. Try to keep your weight loss goals realistic, and remember, keep the calorie-burning muscle, and lose only the fat.