Skinfold Body Fat Calculator

It sums your caliper skinfold readings in millimeters, estimates body density with the sex-specific Jackson-Pollock equation, then converts that density to body fat percent with the Siri equation (495 divided by density, minus 450). The 3-site version uses three folds and the 7-site version uses seven, and both adjust for your age. Enter your weight to also split the result into fat mass and lean mass.

The 3-site method is faster and uses chest, abdomen, and thigh for men or triceps, suprailiac, and thigh for women. The 7-site method adds the midaxillary, subscapular, and remaining folds, which usually tracks better across different body types. Pick 7-site when you can measure every site consistently, and pick 3-site when you want a quick check.

Pinch the fold with your thumb and finger, set the caliper jaws 1 cm away from your fingers, and read the dial after about two seconds. Take every fold on the right side of the body and average two or three readings per site. Men use a diagonal chest fold and a vertical fold beside the navel for the 3-site version, while women use the triceps and the suprailiac fold instead.

With careful technique, the Jackson-Pollock equations usually land within about 3 to 4 percentage points of underwater weighing or a DEXA scan. Accuracy drops if you squeeze too hard, read the caliper too late, or measure the wrong spot. Use the same caliper, sites, and tester each time so the trend stays meaningful even if the absolute number is slightly off.

The American Council on Exercise lists 14 to 17 percent as fitness and 18 to 24 percent as acceptable for men, with 21 to 24 percent as fitness and 25 to 31 percent as acceptable for women. Essential fat sits near 2 to 5 percent for men and 10 to 13 percent for women, and athletes often fall below the fitness range. Treat these bands as general guides rather than strict medical thresholds.

No. This calculator is for education and general fitness tracking, not a substitute for professional medical advice or a clinical body composition assessment. If you need a precise figure or have health concerns, ask a doctor or a qualified practitioner who can run a DEXA, hydrostatic, or air-displacement (Bod Pod) test.