About

Men predominantly store adipose tissue in the abdominal region. This visceral fat is a primary health indicator. This calculator focuses on the relationship between the neck and abdominal circumference to estimate overall density. The exclusion of hip measurements streamlines the process for male physiology. A key feature here is the projection logic. Users can see how their weight would shift if they reduced their body fat to single-digit percentages while maintaining muscle mass. Ensure the abdomen is measured at the navel and the neck below the larynx.

Formulas

The US Navy formula for men subtracts neck circumference from the abdominal circumference to determine the trunk's taper.

BF = 4951.0324 − 0.19077 × log₁₀waist − neck + 0.15456 × log₁₀height − 450

Constraint: waist > neck is required for the logarithm to be valid.

Reference Data

Category	Range (%)	Visual Description
Essential	2-5%	Veins on abs, striations visible
Athletes	6-13%	Defined six-pack, vascularity
Fitness	14-17%	Upper abs visible, some separation
Average	18-24%	No definition, flat to round look
Obese	≥25%	Round abdomen, no definition

Frequently Asked Questions

Men typically have an android fat distribution pattern where fat accumulates on the trunk rather than the hips. The neck-to-waist ratio is statistically sufficient for male density estimation.

Measure at the level of the navel (belly button). Do not suck in your stomach. Keep the tape measure level around the body.

This metric reverses the equation to show what your weight would be at a shredded 10% body fat. It helps set realistic cutting goals by revealing your current underlying muscle mass.

Mathematically, the formula requires waist minus neck to be positive. Physiologically, it is extremely rare for a waist to be smaller than a neck unless there is a measurement error or extreme anatomy.