3-site skinfold test: a practical guide (mm)
The Jackson-Pollock 3-site skinfold test estimates body fat % using caliper measurements at three sites plus age. It’s popular because it’s:
- relatively low cost,
- repeatable at home,
- useful for trend tracking when you measure consistently.
Use the free calculator
What “3-site” means (male vs female sites)
The classic Jackson-Pollock sites differ by sex:
- Male: chest, abdomen, thigh
- Female: triceps, suprailiac, thigh
In our tool, inputs are millimeters (mm).
How to take skinfold measurements (step-by-step)
- Measure on bare skin (or very thin clothing if you must, but be consistent)
- Pinch the skinfold with your fingers, then place the caliper about 1 cm away from your fingers
- Wait ~1–2 seconds, then read the value (don’t wait too long)
- Take 2–3 readings per site and use the average
- Measure the same side of the body each time (commonly the right side)
If you’re new, expect a learning curve—technique matters.
How to interpret the result (what it’s good for)
Skinfold estimates can be “wrong” in absolute terms, but still useful:
- if you use the same caliper,
- measure the same locations,
- repeat under similar conditions.
Treat it like a trend tool, not a medical measurement.
Skinfold vs tape vs DEXA (why results disagree)
It’s common for these methods to disagree on absolute %:
- Tape tests are circumference-ratio models
- BIA scales depend on hydration and device algorithms
- DEXA is often more accurate, but still variable
Learn the tradeoffs:
Try the other methods:
Common mistakes
- Using cm instead of mm (skinfolds are mm)
- Pinching too much tissue (including muscle)
- Measuring at inconsistent sites week-to-week
- Comparing your skinfold % directly with a BIA scale number
- Expecting day-to-day stability (water/sleep/stress can shift readings)