Skinfold Body Fat Calculator

What Is Skinfold Caliper Body Fat Testing?

Skinfold measurement with body fat calipers is one of the most accessible and proven anthropometric methods for assessing body composition. By pinching subcutaneous adipose tissue at standardized anatomical sites, calipers measure fat layer thickness in millimeters ($mm$). Validated regression equations convert these sums into estimated total body density and body fat percentage.

Supported Skinfold Formulas

This calculator supports the major gold-standard formulas in exercise physiology and sports science:

• Durnin & Womersley (4 Sites): Uses the sum of four skinfolds: Biceps, Triceps, Subscapular, and Suprailiac. Body density is estimated as: $$D = c - m \times \log_{10}(\sum \text{skinfolds})$$ where $c$ and $m$ are age- and sex-stratified regression constants. It is renowned for its reliability across general adult populations and older age groups.
• Jackson & Pollock 3-Site: A rapid assessment protocol using sex-specific sites:
  • Men: Chest, Abdomen, Thigh.
  • Women: Triceps, Suprailiac, Thigh.
• Jackson & Pollock 7-Site: The comprehensive athletic standard measuring: Chest, Midaxillary, Triceps, Subscapular, Abdomen, Suprailiac, and Thigh.

Converting Body Density to Body Fat Percentage

Calculated body density ($D$) is converted into body fat percentage using the standard Siri Equation:

$$\text{Body Fat } (\%) = \left(\frac{495}{D}\right) - 450$$

Lean Body Mass (LBM) and Fat Mass (FM) are then derived from total body weight:

$$\text{Fat Mass} = \text{Weight} \times \left(\frac{\text{Body Fat } \%}{100}\right)$$

$$\text{Lean Body Mass} = \text{Weight} - \text{Fat Mass}$$

Guidelines for Accurate Caliper Measurement

• Always perform measurements on the right side of the subject's body in a relaxed standing posture.
• Grasp the skinfold firmly between thumb and index finger $1\text{ cm}$ above the measurement site, pulling the subcutaneous fat away from the underlying muscle tissue.
• Place the caliper jaws perpendicular to the fold and release the caliper trigger. Read the measurement within $1\text{–}2\text{ seconds}$.
• Take 2 to 3 consecutive measurements at each site and record the average.
• Cross-check your results with other body composition tools like the Body Fat Calculator, Relative Fat Mass Calculator, and RMR Calculator.