Skinfold Body Fat Calculator (Jackson-Pollock 3-Site)

Estimate body fat percentage from three skinfold measurements using the Jackson-Pollock formula.

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Gender

Age

Site 1 (mm) — chest / triceps

Site 2 (mm) — abdomen / suprailiac

Site 3 (mm) — thigh

Result

Enter values to calculate.

Summary

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Detail

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Estimate body fat percentage from three skinfold measurements using the Jackson-Pollock formula.

How It Works

How Skinfold Body Fat Calculator (Jackson-Pollock 3-Site) Works

The three skinfold measurements are added together and combined with age using the Jackson-Pollock regression equation (a different formula for men and women, reflecting different typical fat distribution patterns) to estimate body density, which is then converted into a body fat percentage using the Siri equation.

Real-World Use Cases

Who Uses Skinfold Body Fat Calculator (Jackson-Pollock 3-Site) and Why

Estimating body fat percentage using a skinfold caliper at home or in a gym, without access to more expensive body composition equipment.
Tracking body fat percentage trend over months of training using the same tester and technique for consistency.
Cross-checking a trainer or coach's caliper-based reading using the same Jackson-Pollock formula and inputs.
Comparing skinfold-based results against another estimation method (like RFM or BAI) available elsewhere on the site.

Common Mistakes

Mistakes to Avoid

Measuring at the wrong sites for your gender — the calculator's FAQ specifies chest, abdomen, and thigh for men versus triceps, suprailiac, and thigh for women, and using the wrong set produces a meaningless result.
Switching testers or technique between measurements and expecting a consistent trend — the FAQ is explicit that results vary noticeably between different testers, so comparing your result against someone else's single reading (rather than your own trend) isn't meaningful.
Using an inexpensive or poorly calibrated caliper inconsistently (pinching too much or too little skin), which introduces error that the formula has no way to correct for.

Pro Tips

Tips for Best Results

Have the same person take your measurements each time, using the same technique, since the calculator's FAQ notes tester consistency matters more for tracking than almost any other factor.
Take each skinfold measurement two or three times and average them, since even a skilled tester's individual pinches can vary slightly.

Troubleshooting

Fixing Common Problems

My body fat percentage jumped noticeably between two measurements a week apart. — A change that large in a week is more likely measurement variation (different tester, different technique, different time of day) than an actual body fat change — check that the same person and method were used both times before trusting the difference as real.

Glossary

Terms Explained

Jackson-Pollock formula: A regression equation that estimates body density from skinfold thickness measurements at specific body sites, using separate versions for men and women.

Siri equation: A standard formula that converts an estimated body density figure into a body fat percentage.

FAQ

Frequently Asked Questions

Which three sites should I measure?

For men, the standard sites are chest, abdomen, and thigh; for women, they're triceps, suprailiac (just above the hip bone), and thigh — using a proper skinfold caliper and consistent technique matters more for accuracy than almost any other factor here.

How accurate is skinfold testing compared to other methods?

In experienced hands it's a solid, inexpensive estimate, but accuracy depends heavily on measurement technique and consistency — results can vary noticeably between different testers, so tracking your own trend over time with the same tester matters more than comparing a single reading against someone else's.