Body Fat Calculator

Calculate your body fat ratio and lean mass split using the standard US Navy Circumference guidelines.

Height (cm)
Weight (kg)
Neck Circumference (cm)
Waist Circumference (cm)

Body Fat Breakdown

Body Fat

16.4%

Classification

Fitness

Fat Mass

11.5 kg

Lean Mass

58.5 kg

Understanding Body Fat Percentage

Your body fat percentage is the total mass of fat divided by total body mass. Unlike weight or BMI, body fat percentage explicitly describes your body composition, separating active muscular structure (lean mass) from stored lipid reserves (fat mass).

Body fat is divided into two categories: essential body fat and storage body fat. Essential fat is required to sustain physiological safety, reproductive hormones, and temperature insulation. Storage fat is energy accumulated as fat reserves in adipose tissues.

US Navy Circumference Method Formulas

This calculator implements the official mathematical equations used by the US Navy to estimate body fat, which are highly accurate for general athletic profiling:

Men:   BF% = 86.010 * log10(Waist - Neck) - 70.041 * log10(Height) + 36.76
Women: BF% = 163.205 * log10(Waist + Hip - Neck) - 97.684 * log10(Height) - 78.387
            

Standard Body Fat Classifications

Category Men Range (%) Women Range (%)
Essential Fat 2% to 5% 10% to 13%
Athletes 6% to 13% 14% to 20%
Fitness 14% to 17% 21% to 24%
Average 18% to 24% 25% to 31%
Obese / High Risk 25% or Higher 32% or Higher