What is the US Navy body fat method?

It estimates body fat from a few tape measurements, neck and waist for men, plus hip for women, along with height. It is a quick, no-equipment way to track body composition that correlates reasonably with more precise methods for most people.

It is an estimate, typically within a few percentage points of methods like DEXA for average builds, but less reliable for very muscular or very lean people. Its real value is consistency: measured the same way over time, it tracks changes well.

What is a healthy body fat percentage?

Healthy ranges differ by sex and age, but broadly around 10 to 20 percent for men and 18 to 28 percent for women are often cited as healthy. This is general information, not medical advice; talk to a health professional for guidance.

Body Fat Percentage Calculator

This calculator estimates your body fat percentage using the US Navy tape method, a quick way to gauge body composition in New Zealand from a few measurements and no special equipment. The bathroom scales tell you your weight but nothing about how much of it is fat versus muscle, and methods like DEXA scans or callipers need a clinic or skill, so the Navy method has become popular precisely because anyone can do it at home with a soft tape measure. It works from the circumference of your neck and waist for men, with the hip added for women, together with your height, and applies a formula developed by the US Navy that correlates reasonably well with more precise methods for people of average build. You choose your sex, enter your height, neck and waist measurements in centimetres, and your hip if you are female, and the calculator returns your estimated body fat percentage. It is an estimate, most accurate for typical builds and less so for very muscular or very lean people, but its real strength is consistency: measured the same way each time, it tracks changes in your body composition over weeks and months far better than weight alone. Healthy ranges differ by sex and age. This is general information, not medical advice; speak to a health professional for guidance.

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Sex

Height (cm)

Neck (cm)

Waist (cm)

Hip (cm, women)

13.7%

estimated body fat percentage (US Navy method)

An estimate, most accurate for average builds. Measure consistently to track change over time. General information, not medical advice.

How it works

For men, body fat percentage is 495 divided by (1.0324 minus 0.19077 times the log of waist minus neck, plus 0.15456 times the log of height), minus 450. For women, it uses 495 divided by (1.29579 minus 0.35004 times the log of waist plus hip minus neck, plus 0.22100 times the log of height), minus 450. The Hodgdon and Beckett coefficients are calibrated for inches, so your centimetre inputs are converted to inches before the formula is applied.

Worked example

A man 178 centimetres tall with a 38 centimetre neck and 90 centimetre waist has a waist-minus-neck of 52 centimetres. Converting to inches (178 cm = 70.08 in, waist-minus-neck = 20.47 in) and applying the formula gives an estimated body fat of about 13.7 percent.

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