Body Fat Calculator: U.S. Navy Method & Lean Body Mass

Body Fat Calculator

Calculate your body fat percentage and body composition using the scientifically validated U.S. Navy circumference method. Compare your results with BMI-based estimates and discover your lean body mass versus fat mass.

Gender

Age (years)

Height

Body Weight

Body Circumference Tape Measurements

Measure around the neck just below the larynx, and around the waist at the narrowest point (or navel level).

Neck Circumference *

Waist Circumference *

Fitness Category

0.0%

Estimated Body Fat Percentage via the U.S. Navy Circumference Method.

U.S. Navy Method

0.0%

Calculated using abdominal, neck, and hip circumference tape equations.

BMI-Based Method

0.0%

Calculated via Deurenberg adult body composition equation: $(1.20 \times \text{BMI}) + (0.23 \times \text{Age})$.

Body Composition Mass Breakdown

Total body weight divided into fat tissue and metabolically active lean mass:

Lean Body Mass

0.0 kg

0% of total

Body Fat Mass

0.0 kg

0% of total

American Council on Exercise (ACE) Classification

Description	Women	Men
Essential Fat	10 – 13%	2 – 5%
Athletes	14 – 20%	6 – 13%
Fitness	21 – 24%	14 – 17%
Average	25 – 31%	18 – 24%
Obese	32%+	25%+

How the U.S. Navy Body Fat Method Works

Developed by the Naval Health Research Center, the U.S. Navy formula estimates body density using neck, waist, height, and (for females) hip tape circumferences. Body density is then converted into body fat percentage via the Siri equation.

Men: Uses height, neck, and waist measurements.
Women: Incorporates hip measurements alongside waist, neck, and height to account for natural gynoid fat distribution.