Jackson Pollock 3site Male Bodyfat
Calculator

The male 3-site protocol measures skinfold thickness at the chest, abdomen, and thigh, using calipers to pinch and measure each fold. These three measurements plus age are entered into a regression equation to estimate body density and then body fat percentage.

The sum of the three skinfold measurements and age are plugged into the Jackson-Pollock regression formula to estimate body density, which is then converted to body fat percentage using the Siri equation. Each step introduces some estimation error, so the final number is an approximation, not a lab-grade measurement.

Skinfold methods are typically accurate within about 3-4% body fat for an experienced tester, less accurate than DEXA but far more accessible and affordable. Accuracy depends heavily on measurement technique, so inconsistent caliper use between tests undermines the result.

Skinfold measurement technique varies significantly between testers, including how the fold is pinched and exactly where on the body it's measured, so switching testers can introduce artificial swings in tracked results. Using the same person and the same measurement sites each time gives more reliable trend data than absolute accuracy.

The Jackson-Pollock equations were validated on a general population and tend to be less precise at the extremes of the body fat spectrum, where skinfold-to-total-fat relationships behave differently. For individuals far from average body composition, other methods may give a more reliable estimate.