The Jackson-Pollock Skinfold Method
The Jackson-Pollock 3-site skinfold method is a widely used, validated technique for estimating body fat percentage using skinfold calipers. For men, measurements are taken at the chest, abdomen, and thigh. For women, at the tricep, suprailiac (above the hip bone), and thigh. The sum of these three measurements, combined with age, is entered into the Siri density equation to estimate body fat percentage.
Accuracy
When performed correctly by a trained measurer, the JP3 method has a standard error of approximately 3.5% compared to hydrostatic weighing. Key sources of error include measurement technique, caliper quality, and biological variation (skin compressibility). Consistency in measurement site and technique is more important than absolute precision.
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Content reviewed for accuracy using guidelines and research from the WHO, CDC, NIH, and peer-reviewed academic journals.
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Frequently Asked Questions
How accurate are skinfold measurements?
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When performed consistently by a trained measurer, skinfold measurements have a standard error of approximately 3–4% compared to hydrostatic weighing. Intra-rater reliability (same person measuring repeatedly) is typically high; inter-rater reliability (different measurers) varies.
How do I take skinfold measurements accurately?
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Use calibrated skinfold calipers. Pinch the skin firmly between thumb and forefinger, pulling it away from the underlying muscle, and apply the calipers 1cm from your fingers. Take three measurements at each site and average them. Measurements should be taken on the right side of the body, in a consistent sequence. For best accuracy, have the same person take measurements each time using the same calipers.
Is the skinfold method or the Navy method more accurate?
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When performed by a trained measurer, the 3-site Jackson-Pollock skinfold method has a standard error of approximately 3.5%. The Navy circumference method has a similar error of 3–4%. For self-measurement, the Navy method is generally more reproducible because circumference measurements are less technique-dependent than skinfold pinching.
Where do I measure for the Jackson-Pollock 3-site method?
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Men: chest (diagonal fold midway between the armpit and nipple), abdomen (vertical fold 2cm to the right of the navel), thigh (vertical fold on the front of the thigh midway between hip and knee). Women: tricep (vertical fold at the midpoint of the back of the upper arm), suprailiac (diagonal fold just above the hip crest), thigh (same as men).