Army Body Fat Calculator

How the Army measures body fat

The US Army checks body composition in two places. Applicants are screened against the maximum body fat allowed for entry (Army Regulation 40-501, Standards of Medical Fitness), and serving soldiers are held to the Army Body Composition Program (Army Regulation 600-9). Both rely on a circumference-based tape assessment rather than a scale alone.

Until mid-2023 the assessment combined height, neck, waist and, for women, hip measurements. After a large study of soldiers the Army replaced it with a single-site test that needs only weight and the circumference of the abdomen. This calculator handles both: choose New tape test (single-site) or Old tape test at the top of the form.

The result is an estimate. Only a measurement taken by a trained person under Army procedures is official.

The new single-site tape test

Enter your gender, your age in whole years, your weight in pounds and the circumference of your abdomen in inches, measured at the level of the navel. The calculator then applies the linear equation for your sex, with weight (W) in pounds and abdominal circumference (AC) in inches:

Men: body fat % = −26.97 − 0.12 × W + 1.99 × AC

Women: body fat % = −9.15 − 0.015 × W + 1.27 × AC

Example, man. Age 30, 180 lb, abdomen 36 in: −26.97 − 21.6 + 71.64 = 23.07 percent.

Example, woman. Age 30, 150 lb, abdomen 34 in: −9.15 − 2.25 + 43.18 = 31.78 percent.

The same weight with a bigger waist gives a higher result, while for a given waist a heavier person scores slightly lower, because more weight at the same abdominal size implies more lean tissue. A result below 0 or above 75 percent is rejected as unrealistic.

The old multi-site tape test

Select Old tape test to use the previous method, which estimates body fat from the logarithms of the circumferences and height. With every measurement in inches:

Men: body fat % = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76

Women: body fat % = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387

Metric inputs use the same equations with the final constant changed to 30.30 for men and −104.912 for women, so centimetres can go in directly. Feet and inches are entered in separate boxes and added together.

Example, man. Height 5 ft 10 in (70 in), neck 1 ft 3 in (15 in), waist 2 ft 10 in (34 in): 86.010 × log₁₀(19) − 70.041 × log₁₀(70) + 36.76 = 86.010 × 1.2788 − 70.041 × 1.8451 + 36.76 ≈ 17.51 percent.

Example, woman. Height 5 ft 5 in (65 in), neck 13 in, waist 31 in, hip 38 in: 163.205 × log₁₀(56) − 97.684 × log₁₀(65) − 78.387 ≈ 29.83 percent.

A waist that is narrower than the neck cannot be used in the logarithm; the calculator then shows "nan" as the result.

The standards you are measured against

Two sets of maximum body fat percentages apply, both by sex and age group. The first is the limit for entering the Army; the second is the limit to stay in good standing under the body composition program.

The Department of Defense also names a long-term goal of 18 percent for men and 26 percent for women. Nobody is required to reach it, but the calculator shows how far you are from it. Use whole-number ages: an age such as 27.9 sits between two bands, so you will get the percentage without any verdicts, and anyone under 17 is told they are too young to apply.

Reading the verdict lines

After the estimate you see three lines. Each one either says you meet the limit, or says how much you would need to lose. The message gives two numbers, and they are easy to confuse:

• Percent of your body fat: the share of your current fat you would have to lose, written as a plain percentage.
• Percentage points (p.p.): the drop in your body fat percentage itself, from where you are to the limit.

Take the 23.07 percent man aged 30. He meets the entry limit of 28 and the standard of 24. The goal is 18, which is 5.07 points away. Relative to his current fat that is 5.07 ÷ 23.07 ≈ 22 percent, so the line reads "You need to lose 22% (5.1 p.p.) of your body fat to meet the army goal of 18%".

The woman at 38.80 percent aged 30 faces limits of 34 and 26. For the entry limit the gap is 4.8 points, or 4.8 ÷ 38.80 ≈ 12.4 percent of her body fat. A result exactly at a limit counts as meeting it, but 24.004 percent is above 24 and is flagged even though it is displayed as 24.

Measuring and improving

Measure on bare skin or thin clothing, standing relaxed and breathing out normally. For the new test, wrap the tape level around the abdomen at the navel without pulling the stomach in. The Army takes several readings and averages them; do the same, and have someone else read the tape if you can. Weigh yourself at a consistent time, ideally in the morning.

If your numbers are over a limit, the lever is fat loss with muscle retained: a modest calorie deficit (see the calorie calculator and the weight loss calorie calculator), regular resistance and aerobic training and enough protein. Your TDEE tells you the maintenance level to cut from. For a civilian tape-based estimate of fat and lean mass see the body fat calculator, and for a quick size check the BMI calculator.

This is an unofficial estimate based on published equations and limits, and policy changes over time. Check current Army regulations and directives for what applies to you. It is general information, not medical advice; see the disclaimer.