How to Calculate Body Fat Percentage

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Knowing how to calculate body fat percentage can not be used by itself to determine your risk of obesity health problems, but it can be used to confirm the results of your body mass index test.


If you haven’t done so already, first go to our How to Calculate BMI page to determine your body mass index weight classification.

If you think that your results may be flawed due the limitations discussed on that page and want to take a confirming test before going to your doctor, proceed with a body fat percentage calculation…

The Skinfold Measurement Test
(Body Fat Caliper Measurement)

The Skinfold Measurement Test is one of the most common ways to calculate body fat percentage. It tests your body fat percentage by measuring the thickness of skin folds on specific points along the right side of your body. The thicker your skin folds, the higher your body fat percentage.

In order to proceed, you will need a good caliper (an instrument with two hinged curved legs used to measure thickness) and someone to take your measurements.

The person helping you should pinch your skin and underlying fat, then proceed by using the caliper to measure the skin fold. Skin folds on up to seven parts of the right side of your body can be measured (click here for pictures):

  1. Abdomen – one inch to the right of your navel
  2. Bicep – halfway between your elbow and shoulder
  3. Calf – on the inside of your lower leg on the biggest part of your calf
  4. Chest – halfway between your upper armpit and nipple
  5. Lower back – 2 inches to the right of your spine and just above your kidney
  6. Midaxillary – on your side, just below your armpit
  7. Subscapular – just below your shoulder blade
  8. Suprailiac – just above your iliac crest (between your mid-abdomen and side)
  9. Thigh – halfway between your knee cap and the top of your thigh
  10. Tricep – halfway between your elbow and your shoulder

When pinching the skin and underlying fat, make sure to…

  • Hold the pinch for 2 seconds before measuring, then continue to hold it while measuring.
  • Make sure the caliper is placed perpendicular to the fold of the skin, halfway down the fold.
  • Each part of the body should result in measurements within 1 to 2 millimeters of each other. If they do not, you are not testing correctly.

After getting your measurements, plug them into one of several online calculators. To accurately calculate body fat percentage, the calculators take into account your age and gender.

A reliable and free tool can be found by clicking here. The following explains how to use it and how to interpret the results…

First choose whether you are measuring 7 sites or 3 sites and enter your gender, age, and weight:

calculate body fat percentage

Next enter your measurements for the 3 or 7 body sites (7 body sites make the test more accurate, but 3 should still give you an accurate reading):

calculate body fat percentage

Then click “Calculate”:

calculate body fat percentage

Your information will be displayed in the right column, including your body fat percentage, the average body fat percentage for others in your age and gender category, and your body fat “Rating”:

calculate body fat percentage

If your body mass index (BMI)is above 30 and your body fat percentage rating is “Poor” you should be concerned about obesity health problems. If your BMI is above 35 and your body fat percentage rating is “Poor”, you may be a candidate for bariatric surgery.

Click here to learn whether bariatric treatment may be an option for you.