Army Body Fat Calculator
Estimate body fat using the tape measurement method.
Women only — measure at the widest point.
Results update as you type.
This calculator provides estimates based on population research. Results are not medical advice. Consult a qualified healthcare provider before making health or nutrition decisions.
How it works
The army body fat calculator estimates your body fat percentage from a handful of tape measurements rather than expensive equipment, which is exactly why the method is used for fitness screening in military and tactical settings. It applies the US Navy circumference formula, the same approach adopted by the armed forces to assess whether members meet body-composition standards. Instead of pinching skinfolds or standing in a scanner, you measure your neck and waist, plus hips for women, along with your height, and the equation converts those circumferences into an estimated fat percentage. The logic is that fat accumulates in predictable places, so the girth of the waist relative to the neck and frame reveals roughly how much of your body is fat. Because it needs only a flexible tape, an army body fat calculator is cheap, quick and repeatable at home, making it popular well beyond the military with anyone tracking a cut or a recomposition. Accuracy is reasonable for average builds but can drift for very muscular or unusually shaped individuals, since the tape cannot see internal composition. Measure on bare skin, keep the tape snug and level, take the waist at the navel for men and the narrowest point for women, and measure the neck just below the larynx. Use the same technique each time so your trend is reliable, and treat the figure as a practical screening estimate rather than a laboratory value.
Circumference (US Navy) method using log10 of neck, waist, hip and height
The US Navy method models body fat as a function of the logarithm of circumference differences scaled by height. For men it uses waist minus neck, capturing abdominal fat above the frame's baseline girth; for women it adds hip circumference because women store more fat around the hips. Taking the base-10 logarithm reflects the non-linear way girth relates to fat, and the constants were fitted against hydrostatic-weighing reference data to return a percentage.
Source:US Navy / Naval Health Research Center circumference method
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter sex, height, neck circumference and waist circumference.
- 2
Adjust the options
Adjust hip circumference if they apply — sensible defaults are already set.
- 3
Read your result
Body fat percentage updates instantly as you type — no button to press.
Frequently asked questions
How accurate is the army tape method?
For people of average build it typically lands within about three to four percent of a hydrostatic or DEXA measurement, which is good for a tool needing only a tape. Accuracy falls for very lean, very muscular or unusually proportioned bodies, because circumferences cannot distinguish muscle from fat. It is best used to track changes over time with consistent technique rather than to pin down one exact number, and it should not replace clinical body-composition testing.
Where exactly do I measure my waist and neck?
Measure the neck just below the larynx, or Adam's apple, with the tape sloping slightly down at the front. For men, measure the waist horizontally at the navel; for women, at the narrowest point of the torso. Hips, for women, are measured at the widest point of the buttocks. Keep the tape snug but not compressing the skin, breathe normally, and take each reading two or three times to average out error.
Why do women need a hip measurement but men do not?
Women naturally store a larger share of body fat around the hips and thighs, so the female version of the Navy formula includes hip circumference to capture that fat and return an accurate estimate. Men store proportionally more fat abdominally, which the waist-minus-neck term already reflects, so a hip measurement adds little. Using the correct sex-specific formula matters, because applying the male equation to a woman would understate her body fat.
What is a healthy body fat percentage?
General fitness ranges are roughly 10 to 20 percent for men and 18 to 28 percent for women, with athletes often lower and essential-fat minimums near 3 percent for men and 12 percent for women. Body fat naturally rises with age. These bands are guides, not strict cutoffs, and health depends on more than fat alone. Very low body fat carries its own risks, so extremely lean targets are not advisable for most people.
Is the tape method the same as the Navy calculator?
Yes. The army or military tape method and the US Navy body fat calculator use the same circumference-based equations, developed by the Naval Health Research Center. Different branches set their own pass or fail thresholds and occasionally tweak measuring sites, but the underlying formula converting neck, waist, hip and height into a body fat percentage is identical. This calculator uses that standard equation, so results match typical Navy and army screening tools closely.