No method of measuring body fat percentage is without complications. Hydrostatic weighing can be expensive and time-consuming, while online calculators tend to be inaccurate. Body fat calipers, on the other hand, are an inexpensive way to measure your body fat at your convenience. The calipers require pinching the fat in certain areas and measuring its thickness. According to Sports Fitness Advisor, the measurements can be accurate within a 4 percent margin of error if you take them properly.
Taking Measurements
Step 1
Measure the distance between your nipple and your armpit, then make a mark the halfway point if you're male. Women should take the same measurement but make the mark one-third of the way from the armpit to the nipple. Take all measurements on the same side of your body as this one.
Step 2
Pinch the skin at the mark diagonally. Top End Sports recommends pinching between your thumb and forefinger deep enough to get a double-thick pinch of skin without pulling up any muscle, and hard enough to cause slight discomfort.
Step 3
Locate crest formation, where the pinched skin is farthest from the body, and a base, where it's closest. Place the calipers halfway between the crest and the base. This is usually about 1 cm below the pinch.
Step 4
Hold the pinch for two seconds, then adjust the calipers so they close on the skinfold. Read the measurement, release the skin and record the measurement in millimeters. Keep the pinching technique in Steps 2 through 4 consistent for all measurements.
Step 5
Pinch the skin vertically under the center of your armpit, at the level right under your nipple. Measure the skinfold and record the result. Continue recording the results after each measurement.
Step 6
Make a mark one inch to the side of your belly button on the side of your body where you're taking the other measurements. Pinch vertically at the mark and measure.
Step 7
Pinch diagonally just above the forward protrusion of your hip bone and measure.
Step 8
Make a mark halfway between your elbow and shoulder. Pinch vertically at the mark and measure.
Step 9
Make a mark halfway between the top of your thigh and your knee. Pinch vertically at the mark and measure.
Step 10
Ask a partner to pinch diagonally directly under your shoulder blade and take the measurement.
Step 11
Take all measurements in steps 1 through 10 two more times, using the marks you've already made. If subsequent measurements are more than 2 mm off from your first, take the measurements again, keeping your technique consistent.
Calculations
Step 1
Average your three sets of measurements.
Step 2
Calculate your bone density. According to the Build Muscle and Gain Weight Fast Guide website, women should use the following equation: 1.097 - (0.00046971 x SUM7) + (0.00000056 x SUM7²) - (0.00012828 x AGE).
Substitute the sum of your seven measurements for "SUM7" and your age for "Age." For men, use this equation: 1.112 - (0.00043499 x SUM7) + (0.00000055 x SUM7²) - (0.00028826 x Age).
Step 3
Substitute the result of the bone density calculation for "Bone Density" in the following equation: [(4.95/Bone Density) - 4.5] 100. The result is the body fat percentage based on your measurements.
Note that other body fat percentage equations may be more appropriate for your body type. The "International Journal of Obesity" reports that age and race play a role in determining healthy body fat percentages.
Tips and Warnings
- If you take measurements on different days, take them at the same time of day. If you're having someone else take the measurements, have the same person take them every time. You can track your fat loss progress by simply comparing your caliper measurements, rather than calculating your body fat percentage, which introduces a new margin for error. Do not take your measurements immediately after exercising, as this can lead to inaccurate results.
Things You'll Need
- Body fat calipers
- Felt pen
- Tape measure
- Calculator
References
- Sports Fitness Advisor: How to Use Body Fat Calipers and Make Them More Reliable
- The Build Muscle and Gain Weight Fast Guide: How to Take Skinfold Measurements and Calculate Body Fat Percentage
- Top End Sports: Skinfold Measurement
- Linear Software: Online Body Fat Calculator for Men and Women
- International Journal of Obesity: The Effect of Sex, Age and Race on Estimating Percentage Body Fat from Body Mass Index
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