Body Fat Calculator

Estimate your body fat percentage from a tape measure using the US Navy method. See your category, a colour scale and, if you add your weight, your fat and lean mass. Nothing you type is stored.

Height

Neck (below the larynx)

Waist (at the navel)

Weight (optional)

Measure with a soft tape on bare skin, standing relaxed, and breathe out before reading the waist.

Estimated body fat

21.5%

Category: Average (American Council on Exercise ranges for men).

Essential fat2% to 5%
Athletes6% to 13%
Fitness14% to 17%
Average18% to 24%
Above average25% and above

The Navy tape-measure method is a convenient estimate, usually within a few percentage points. It is a handy way to track change over time, not a medical measurement.

What body fat percentage is

Body fat percentage is the share of your total weight that is fat. Some fat is essential: it protects organs, stores energy and helps regulate hormones. Too little or too much can affect health, which is why body fat is sometimes used alongside BMI.

The US Navy tape-measure method

The method was developed by the US Navy to estimate body fat without special equipment. It uses height and circumference measurements, with the neck and waist for men, and the neck, waist and hips for women, and works out a body density from the logarithms of those numbers. The result is usually within a few percentage points of more precise methods for average builds.

Body fat categories

Ranges from the American Council on Exercise (ACE). They are general guides, not targets for everyone.

Category	Women	Men
Essential fat	10% to 13%	2% to 5%
Athletes	14% to 20%	6% to 13%
Fitness	21% to 24%	14% to 17%
Average	25% to 31%	18% to 24%
Above average	32% and above	25% and above

How to measure

Use a soft, flexible tape on bare skin and stand relaxed.
Neck: just below the larynx (Adam's apple), tape level in front.
Waist: at the navel for men, at the narrowest point for women. Breathe out before reading.
Hips (women): at the widest point of the buttocks.
Measure twice and use the average. Small errors in the waist change the result noticeably.

Limits of this estimate

It can be off by several percentage points compared with DEXA scans or water-immersion tests.
Very muscular, very lean or older people can be misjudged.
Where fat is stored matters for health, and a single number cannot show that.
It is not a diagnosis. Talk to a doctor about your health.

How to use the Body Fat Calculator tool

Choose your sex and units, then type your height.
Measure your neck, your waist (and your hips if you are a woman) with a soft tape and type the numbers.
Optionally add your weight to see fat mass and lean mass.
Read your estimated body fat percentage and the category it falls in.

Frequently asked questions

How does the US Navy body fat method work?

It estimates body fat from the logarithms of your height and body measurements: neck and waist for men, and neck, waist and hips for women. It was developed so that body fat could be estimated with just a tape measure.

How accurate is it?

It is an estimate that can be off by several percentage points compared with methods such as DEXA scans. It works best for average builds, and less well for very muscular or very lean people.

What is a healthy body fat percentage?

It varies with age and sex. The American Council on Exercise lists about 14% to 20% for women athletes and 6% to 13% for men athletes, and about 25% to 31% for women and 18% to 24% for men as average. Some fat is essential for health.

Where should I measure?

Measure the neck just below the larynx, the waist at the navel for men or the narrowest point for women, and the hips at their widest point. Stand relaxed, keep the tape snug but not tight, and breathe out before reading.

Is this a medical test?

No. It is a rough estimate for general interest. A doctor can give you a proper assessment of your health and body composition.