The Fitties Journal
Jackson-Pollock 3-Site Skinfold Body Fat Calculator
Key Takeaways
Here's what matters most if you're short on time.
- The Jackson-Pollock 3-site method uses chest, abdomen, and thigh measurements for males, and tricep, suprailiac, and thigh measurements for females.
- One of the simplest caliper-based formulas, needing only three skinfold measurements, your age, and basic math. No scale is needed.
- Expect a margin of error of a few percentage points. The equations were built on general adult samples, so they are less tested in very lean or highly trained people.
The Jackson-Pollock 3-site body fat test, developed by researchers Dr. Andrew Jackson and M. L. Pollock (Jackson and Pollock, 1978), is a caliper-based method for estimating body fat percentage. Skinfold testing remains one of the most widely used ways to estimate body fat in clinical and sports settings (Cintra et al., 2026). The 3-site version needs only three skinfold measurements and your age and sex. No scale is needed.
This method is popular because it is simple. All you need is a set of skinfold calipers and a few minutes. You can take most sites on yourself, though a partner makes the chest and triceps sites easier.
For a complete overview of all body fat measurement methods and how to use calipers, see our guide to measuring body fat.
If you don't have calipers, the US Navy body fat formula estimates body fat from simple tape-measure circumferences instead.
What Is the 3-Site Skinfold Test?
The 3-site skinfold test, also called the 3-point caliper test, estimates body fat from the thickness of three skinfolds. At each site you pinch a fold of skin and the fat beneath it, measure it with calipers in millimeters, and add the three readings together. The Jackson-Pollock equation turns that sum and your age into body density, and the Siri equation turns body density into a body fat percentage.
Men measure the chest, abdomen and thigh. Women measure the triceps, suprailiac (just above the hip bone) and thigh. The two sets differ because the men's and women's equations come from two separate studies (Jackson and Pollock, 1978; Jackson, Pollock and Ward, 1980).
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Shop FitNutrients+Who Is This Method For?
The Jackson-Pollock 3-site method is a good fit for most people of average build who want a quick, accessible body fat estimate. It is one of the fastest caliper-based formulas to perform and does not require reaching difficult anatomical landmarks.
The equations were built on general adult samples, 308 men aged 18 to 61 (Jackson and Pollock, 1978) and 249 women aged 18 to 55 (Jackson, Pollock and Ward, 1980). How well they work in very lean or highly trained people is less well established. If that describes you, consider the Yuhasz method (designed for athletes). If you want more of the body measured, the Jackson-Pollock 7-site method uses seven sites.
Skinfold Measurement Locations
Men and women measure different sites. Use the table that matches the equation you use.
Male Measurement Sites
| Site | Location | Fold Direction |
|---|---|---|
| Chest (Pectoral) | Halfway between the nipple and the upper portion of the pectoral muscle near the armpit | Diagonal |
| Abdomen | One inch to the right of the belly button | Vertical |
| Thigh | Halfway between the kneecap (patella) and the inguinal crease (where the top of the thigh meets the hip) | Vertical |
Female Measurement Sites
| Site | Location | Fold Direction |
|---|---|---|
| Tricep | Halfway between the top of the shoulder and the elbow, on the back of the arm | Vertical |
| Suprailiac | Above the superior anterior iliac crest (the upper and forward protrusion of the hip bone) | Diagonal |
| Thigh | Halfway between the kneecap (patella) and the inguinal crease (where the top of the thigh meets the hip) | Vertical |
Jackson-Pollock 3-Site Formula for Males
Measure the following skinfolds in millimeters with body fat calipers. They are Chest (Pectoral), Abdomen, and Thigh.
| Step | Formula |
|---|---|
| Body Density | 1.10938 - (0.0008267 x sum of skinfolds) + (0.0000016 x sum of skinfolds²) - (0.0002574 x age) |
| Body Fat % | (495 / Body Density) - 450 |
Jackson-Pollock 3-Site Formula for Females
Measure the following skinfolds in millimeters with body fat calipers. They are Tricep, Suprailiac, and Thigh. The female equations come from a separate study (Jackson, Pollock and Ward, 1980), which is why the measurement sites differ from the male formula.
| Step | Formula |
|---|---|
| Body Density | 1.0994921 - (0.0009929 x sum of skinfolds) + (0.0000023 x sum of skinfolds²) - (0.0001392 x age) |
| Body Fat % | (495 / Body Density) - 450 |
Example Calculation
Here is a worked example for a 30-year-old male with the following skinfold measurements.
| Site | Measurement |
|---|---|
| Chest | 12 mm |
| Abdomen | 18 mm |
| Thigh | 15 mm |
| Sum of Skinfolds | 45 mm |
Step 1: Calculate Body Density
Body Density = 1.10938 - (0.0008267 x 45) + (0.0000016 x 45²) - (0.0002574 x 30)
Body Density = 1.10938 - 0.037202 + 0.00324 - 0.007722
Body Density = 1.067696
Step 2: Convert to Body Fat Percentage
This step uses the Siri equation, which converts body density into a percentage.
Body Fat % = (495 / 1.067696) - 450
Body Fat % = 463.61 - 450
Body Fat % = 13.6%
3-Site Skinfold Chart
These charts come from the same equations as the calculator above. Find your sum of three skinfolds in the left column and read across to the age closest to yours. If your age or sum falls between two columns or rows, your estimate falls between the two figures.
3-Site Skinfold Chart for Men (Chest, Abdomen, Thigh)
| Sum of 3 skinfolds (mm) | Age 20 | Age 30 | Age 40 | Age 50 | Age 60 |
|---|---|---|---|---|---|
| 20 | 4.8% | 5.9% | 7.0% | 8.1% | 9.2% |
| 30 | 8.0% | 9.1% | 10.2% | 11.3% | 12.4% |
| 40 | 11.0% | 12.1% | 13.2% | 14.4% | 15.5% |
| 50 | 14.0% | 15.1% | 16.2% | 17.3% | 18.5% |
| 60 | 16.8% | 17.9% | 19.1% | 20.2% | 21.4% |
| 70 | 19.5% | 20.7% | 21.9% | 23.0% | 24.2% |
| 80 | 22.2% | 23.3% | 24.5% | 25.7% | 26.9% |
| 90 | 24.7% | 25.9% | 27.0% | 28.2% | 29.4% |
| 100 | 27.1% | 28.3% | 29.5% | 30.7% | 31.9% |
| 110 | 29.3% | 30.5% | 31.7% | 33.0% | 34.2% |
3-Site Skinfold Chart for Women (Triceps, Suprailiac, Thigh)
| Sum of 3 skinfolds (mm) | Age 20 | Age 30 | Age 40 | Age 50 |
|---|---|---|---|---|
| 30 | 13.1% | 13.7% | 14.3% | 14.9% |
| 40 | 16.7% | 17.3% | 17.9% | 18.5% |
| 50 | 20.2% | 20.8% | 21.4% | 22.0% |
| 60 | 23.5% | 24.1% | 24.8% | 25.4% |
| 70 | 26.7% | 27.3% | 27.9% | 28.6% |
| 80 | 29.7% | 30.3% | 31.0% | 31.6% |
| 90 | 32.5% | 33.1% | 33.8% | 34.4% |
| 100 | 35.1% | 35.8% | 36.4% | 37.1% |
| 110 | 37.5% | 38.2% | 38.9% | 39.5% |
| 120 | 39.8% | 40.4% | 41.1% | 41.8% |
Read every figure as an estimate. Published standard errors for these equations are about 3.4 percentage points of body fat for men and 3.9 for women (Escamilla et al., 2024). The charts stop at age 60 for men and 50 for women because the original samples ended at 61 and 55, and the women's study advised extra care above age 40 (Jackson, Pollock and Ward, 1980).
Tips for Accurate Results
Measure at the same time of day. Morning measurements before eating produce the most consistent results. Hydration, meals, and exercise all affect skinfold thickness.
Take each measurement twice. If the two readings at a site differ by more than 2 mm, take a third and average the two closest. Rotate through all three sites before going back to remeasure, giving the skin time to return to its normal thickness.
Always measure from the right side. The Jackson-Pollock formulas were developed using right-side measurements. Switching sides introduces inconsistency.
Use the same calipers every time. Different caliper brands apply different jaw pressures, so results are not directly comparable across brands.
Track monthly. Body fat changes gradually. Monthly measurements provide meaningful data. Weekly or daily measurements mostly capture noise from hydration and glycogen fluctuations.
How the JP 3-Site Compares to Other Methods
| Method | Sites | Best For |
|---|---|---|
| JP 3-Site (this article) | 3 | Quick estimate, beginners, solo measurement |
| JP 4-Site | 4 | Same four sites for men and women |
| JP 7-Site | 7 | Most comprehensive JP method |
| Durnin-Womersley | 4 | Broad age range (16-72), clinical use |
| Yuhasz | 6 | Athletes and highly fit individuals |
| Parillo | 9 | Most detailed caliper method |
Where Do Supplements Fit?
Tracking your body fat gives you a baseline. Your training and your diet are what move that number. If you use a multivitamin to cover gaps that food alone may not, FitNutrients+ is one example, a four-capsule daily formula with metabolically active B vitamins such as methylcobalamin and methylfolate, 12.5 mcg (500 IU) of vitamin D3 and Albion mineral chelates. It contains no iron.
Conclusion
The Jackson-Pollock 3-site method is one of the fastest and most accessible ways to estimate body fat with calipers. Three measurements, a simple formula and a set of calipers. Measure the same way each time so your readings are comparable.
If you want the same sites for men and women, try the JP 4-site method. If you want more of the body measured, the JP 7-site method uses seven sites.
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A premium multivitamin/mineral formula, four capsules a day, with metabolically active B vitamins such as methylcobalamin and methylfolate, 12.5 mcg (500 IU) of vitamin D3 and Albion mineral chelates. It contains no iron.
Shop FitNutrients+
