Age
Record in yearsThis is a recorded input rather than a body measurement site.
Enter your current age alongside the physical measurements.
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Method guide
Jackson & Pollock 4-Site Body Fat Calculator
Uses age plus abdomen, thigh, triceps and suprailiac skinfolds.
Calculate
- Accuracy
- ±3.5-4.5%Typical error against a reference method
- Equipment
- skinfold calipers
- Measurement count
- 5
Counts include age, weight and height when required.
How to measure
How to take the measurements
Equipment and Good Technique
Use skinfold calipers on bare, dry skin. Mark every landmark before starting. Grasp skin and the fat beneath it between thumb and forefinger, lift the fold away from the muscle, and keep holding it while the caliper jaws close slightly below your fingers. The jaws stay perpendicular to the fold even when the fold itself is diagonal.
Required Inputs and Measurement Locations
Measure every item listed for your calculation. Labels show when an input applies only to men or women.
Abdomen Skinfold
Record in mmOn the abdomen near the navel.
Fold direction: vertical.
Relax the abdomen, mark the same point beside the navel, and lift the fold away from the abdominal wall.
Thigh Skinfold
Record in mmOn the front of the thigh, halfway between the hip and knee.
Fold direction: vertical.
Unweight the measured leg, mark the midpoint, and lift the relaxed fold vertically.
Tricep Skinfold
Record in mmOn the back of the upper arm, halfway between the shoulder and elbow.
Fold direction: vertical.
Let the arm hang, mark the midpoint behind it, and lift vertically without tensing the triceps.
Suprailiac Skinfold
Record in mmJust above the upper edge of the hip bone.
Fold direction: diagonal.
Find the hip bone’s upper edge, mark just above it, and follow the natural diagonal fold.
Measurement Protocol
Follow this sequence
- Mark the abdomen, thigh, triceps and suprailiac sites on the right side before starting.
- Measure on bare, dry skin while standing with the measured area relaxed.
- Take one reading at each marked site, waiting briefly before recording the caliper value.
- Rotate through all sites for repeat readings rather than completing one site at a time.
- Average only consistent readings; when they disagree, check the landmark, fold direction and caliper position before repeating.
Accuracy and mistakes
How accurate is the Jackson & Pollock 4-Site method?
Jackson & Pollock 4-Site has an estimated accuracy range of ±3.5–4.5% with proper technique. Use that range alongside the method’s practical limitations when deciding whether it suits your measurements.
Who it suits: Caliper users who want a fixed sequence that does not change with the selected gender.
The trade-off: It sits between the shorter and longer Jackson & Pollock protocols while still requiring reliable arm, torso and thigh technique.
What This Method Measures
Uses age plus abdomen, thigh, triceps and suprailiac skinfolds.
Jackson & Pollock 4-Site combines age with skinfolds at the abdomen, thigh, triceps and suprailiac. Men and women use the same required inputs, so every session can follow one repeatable sequence.
It suits a caliper user who wants broader site coverage without taking the longest Jackson & Pollock set. That middle ground still depends on distinct landmarks and multiple fold directions, so a consistent sequence helps prevent a site or direction from being skipped.
- Required inputs
- 5 per calculation.
- Equipment
- Prepare skinfold calipers.
Common mistakes that change the result
- Using a diagonal pinch at the vertical abdomen, thigh or triceps sites.
- Using a vertical pinch for the diagonal suprailiac fold.
- Measuring the thigh while its muscles are supporting most of the body weight.
- Changing the order and location of the required sites between sessions.
- Entering the fold readings without the required age input.
What the estimate means
The calculator turns the recorded inputs into a body fat percentage estimate. For Jackson & Pollock 4-Site, the estimated accuracy range is ±3.5–4.5% with proper technique. A range is not a promise that one reading is exact.
Treat the result as an estimate. When tracking changes, compare readings collected with the same method and procedure. A changed tool, landmark, body side, timing or operator can make readings less comparable. The number does not diagnose health or replace qualified advice, and formulas with different inputs are not interchangeable.
How this compares to other methods
Ordered by typical error, lowest first. Counts include age, weight and height when required.
| Method | AccuracyTypical error against a reference method | Measurement count | Equipment |
|---|---|---|---|
| Parrillo | ±3-4% | 10 | skinfold calipers, a body-weight scale |
| Jackson & Pollock 7-Site | ±3-4% | 8 | skinfold calipers |
| Jackson & Pollock 4-SiteCurrent method | ±3.5-4.5% | 5 | skinfold calipers |
| Durnin & Womersley | ±3.5-5% | 5 | skinfold calipers |
| Jackson & Pollock 3-Site | ±4-5% | 4 | skinfold calipers |
| Covert Bailey | ±4-5% | 5 | a soft tape measure |
| U.S. Navy | ±4-6% | 3 for men · 4 for women | a soft tape measure, a reliable way to measure standing height |
| Modified YMCA | ±4-6% | 2 for men · 5 for women | a soft tape measure, a body-weight scale |
| YMCA | ±5-7% | 2 | a soft tape measure, a body-weight scale |
Where to Go Next
Read the evidence guide
Review the sources and limitations behind Jackson & Pollock 4-Site on its paired research page.
View research →Use the calculator app
Take your prepared readings to Body Fat Calculator, select Jackson & Pollock 4-Site, and enter the measurements listed for your calculation.
PRO+ includes measurement history and progress tracking in the app. You can also sync app results with Apple Health on iOS when you enable the integration and grant permission.
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