📏 Skinfold Body Fat Calculator
Enter your age, sex, weight and three skinfold measurements to estimate body fat percentage using the Jackson-Pollock 3-site method.
The Jackson-Pollock 3-site method
Skinfold calipers measure the thickness of a fold of skin and underlying fat at specific sites on the body. The Jackson-Pollock 3-site formula uses the sum of three of these measurements, together with age and sex, to estimate whole-body density, which is then converted to a body fat percentage.
The formula
Men use chest, abdomen and thigh sites; women use triceps, suprailiac and thigh sites. Body density is estimated from a regression equation using the sum of the three skinfolds and age, and body fat percentage is then derived using the Siri equation: Body Fat % = (495 ÷ Body Density) − 450.
- Sites differ by sex: men (chest, abdomen, thigh); women (triceps, suprailiac, thigh)
- Accuracy depends heavily on caliper technique and consistent site location
This tool is for general fitness tracking and educational purposes only. Skinfold measurements are operator-dependent and results can vary between measurers; for precise body composition assessment, consider DEXA scanning or consult a qualified professional.