Body Fat Percentage & Mass Calculator

Estimate body fat percentage and lean muscle mass using skinfold calipers (Jackson-Pollock) or tape measurements (US Navy Method). Detailed regression analysis for accurate fitness tracking.

User Rating 0.0 ★★★★★
Total Usage 1 times
Category Health Nutrition

Tape Measurements (cm)

Is this tool helpful?

Your feedback helps us improve.

★ ★ ★ ★ ★

About

Knowing your weight is not enough. Two people can weigh 200 lbs; one could be an elite athlete with 8% body fat, and the other could be sedentary with 35% body fat. This tool breaks down your body composition into two critical components: Fat Mass (adipose tissue) and Lean Body Mass (muscle, bone, water, organs).

This calculator supports multiple industry-standard methods. The US Navy Method requires only a tape measure and is excellent for general population tracking. The Jackson-Pollock methods (3, 4, or 7-site) utilize skinfold calipers for higher precision, preferred by bodybuilders and personal trainers to track subcutaneous fat changes over time.

body fat lean mass calipers jackson pollock

Formulas

The US Navy Method uses circumference measurements. For men, the formula relates waist and neck size to height:

%Fat = 86.010 × log10(abdomen − neck) − 70.041 × log10(height) + 36.76

For Jackson-Pollock (3-Site), Body Density (BD) is calculated first, then converted to Body Fat % using the Siri Equation:

BD = 1.10938 − 0.0008267sum + 0.0000016sum2 − 0.0002574age
%Fat = (495BD) − 450

Reference Data

ClassificationWomen (% Fat)Men (% Fat)Description
Essential Fat10-13%2-5%Critical for physiological function. Going below this is dangerous.
Athletes14-20%6-13%High performance, visible definition.
Fitness21-24%14-17%Healthy, active, some definition.
Average25-31%18-24%Normal range for general population.
Obese32%+25%+Increased risk of cardiovascular disease.

Frequently Asked Questions

Hydrostatic weighing and DEXA scans are the 'Gold Standard.' Among the methods in this tool, Jackson-Pollock 7-Site is generally considered the most accurate if the calipers are used correctly by a trained professional. The US Navy method is less prone to user error but slightly less precise for very lean individuals.
Common sites include: Chest (pectoral), Abdomen (next to navel), Thigh (front), Tricep (back of arm), Subscapular (below shoulder blade), Suprailiac (above hip bone), and Midaxillary (below armpit).
Hydration levels significantly impact readings, especially with bio-impedance scales. For caliper and tape methods, user error or bloating can cause small variances. It is best to measure at the same time of day under similar conditions.
Lean Body Mass (LBM) is everything in your body that is not fat. This includes muscle, bone, blood, water, and organs. Increasing LBM usually means building muscle, while decreasing LBM usually means muscle loss.