Skinfold Body Fat Calculator
Estimate body fat percentage using the Jackson-Pollock 3-site skinfold measurement method.
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How to use this calculator
The Jackson-Pollock 3-site method uses skinfold caliper measurements at three specific sites to calculate body density. The Siri equation then converts body density into body fat percentage. Different sites are measured for males (chest, abdomen, thigh) and females (tricep, suprailiac, thigh).
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Use skinfold calipers to measure the specified sites — pinch the skin and underlying fat (not muscle) firmly.
- 2
Enter each measurement in millimetres along with your age and gender.
- 3
Your estimated body fat percentage and category will be calculated using the Jackson-Pollock formula.
Frequently asked questions
What sites do I measure for the Jackson-Pollock 3-site test?
For males: chest (diagonal fold halfway between armpit and nipple), abdomen (vertical fold 2cm to the right of the navel), and thigh (vertical fold on the front of the thigh midway between hip and knee). For females: tricep (vertical fold on the back of the upper arm midpoint), suprailiac (diagonal fold just above the hip bone), and thigh (same as males).
How accurate is the skinfold method?
When performed correctly with quality calipers, the Jackson-Pollock 3-site method has a standard error of approximately 3–4% body fat. Accuracy depends heavily on correct site identification and consistent technique. Multiple measurements at each site should be averaged. DEXA scans are the gold standard but cost far more.
What is a healthy body fat percentage?
Healthy ranges differ by gender. For men, fitness-level body fat is typically 14–17%; for women it is 21–24%. Athletes often fall below these ranges. Body fat below essential levels (under 5% for men, under 14% for women) can impair hormonal and organ function.
Skinfold Body Fat Calculator — Jackson-Pollock 3-Site Method
How the Jackson-Pollock 3-Site Skinfold Test Works
The Jackson-Pollock 3-site skinfold test is one of the most validated field methods for estimating body fat percentage. Developed by Andrew Jackson and Michael Pollock in 1978, the method uses a caliper to measure the thickness of subcutaneous fat (the fat layer just under the skin) at three specific anatomical sites. These measurements are entered into a regression equation that predicts whole-body fat percentage by first estimating body density, then converting it to fat percentage using the Siri equation. The method accounts for age because fat distribution shifts with age even when total fat remains constant.
Interpreting Your Body Fat Category
Body fat categories help contextualise your percentage relative to population norms and health outcomes. Essential fat is the minimum needed for vital physiological functions. Athletic ranges are common in competitive athletes who train regularly and manage nutrition carefully. Fitness ranges represent lean, healthy body composition for active non-athletes. Average ranges are associated with good health for most adults. Categories above average (and especially obese ranges) are linked to increased cardiovascular risk, metabolic disease, and reduced quality of life. Use your category as a directional guide rather than a definitive health verdict — body composition is one of many health markers.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →