How to Calculate Your Body Fat From Your Skinfolds

When you hear about Olympic athletes, like Michael Phelps, and his body fat percentage measurement of four percent, you might wonder how your percentage compares. Not many of us have the time to achieve low percentages like full-time athletes; however, it is still an important fact to know about your body. WebMD states that having too much body fat can lead to type 2 diabetes, heart disease, high blood pressure, arthritis, sleep apnea, and stroke. The skinfold method will give you an awareness of your body fat.

Things You'll Need

• Skinfold calipers

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Instructions

• 1

  Skinfold calipers are needed to determine your body fat percentage.

  Locate and prepare the areas of skin you will measure. They should be dry and free of lotions or moisturizers. Women use three skinfold locations: 1. The triceps, halfway between the shoulder and the elbow; 2. Suprailiac, a diagonal fold along the iliac crest, which is an area on your side, slightly above the hipbone, close to your waist; 3. The thigh, halfway between the kneecap and the crease between the leg and hip. Men also take three different measurements: 1. On the chest, above and to the right of a nipple; 2. An abdominal measurement, one inch to the right of the navel; 3. The thigh.

• 2

  Gather skin in the first measurement location. Using both hands, pinch the skin vertically. Let go with your dominant hand, and pick up the calipers. Place the open jaws of the calipers on the skinfold. Observe and record the thickness of pinched skin in millimeters. Take three measurements of each area. Measure the other two positions, according to your gender.

• 3

  Calculate the mean or average result of your three measurements. To find the mean, add the measurements, and divide the total by three. This number represents the mean, or average.

• 4

  Calculate your percentage of body fat by using the formulas below. One is for men, the other for women. If you do not want to do this calculation, check the resource section of this article, which includes a resource table that will let you take the sum of your three measurements and find your percentage of body fat in a glance across the table.

  For men, add your three average measurements, called SUM3 in the equation. Plug your number into the equation, and calculate the bone density first. After you have the bone density number, plug it into the body fat percentage formula:

  Bone Density = 1.0994921 - (0.0009929 * SUM3) + (0.0000023 * SUM3²) - (0.0001392 * AGE)

  Body Fat Percentage = [(4.95/Bone Density) - 4.5] 100

  For women, while the procedure is the same, the numbers in the equation are different. Add your three average measurements, called SUM3 in the equation. Plug your number into the equation, and calculate the bone density first. After you have the bone density number, plug it into the body fat percentage formula:

  Bone Density = 1.0994921 - (0.0009929 * SUM3) + (0.0000023 * SUM3²) - (0.0001392 * AGE)

  Body Fat Percentage = [(4.95/Bone Density) - 4.5] 100