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Measure body fat the official U.S. Army way with our free army body fat calculator. Built on the tape-test formula in Army Regulation 600-9, it turns four simple circumference measurements — height, neck, waist, and (for women) hip — into an instant body fat percentage. No calipers, no lab visit, no cost.
Screening tool only: this calculator estimates body fat from self-reported measurements using the Army's circumference method. It is not a medical device and does not diagnose any health condition. Official results for service must come from trained personnel following full AR 600-9 procedures.
Getting a reliable reading takes less than two minutes and a single flexible tape measure. For the most trustworthy result, follow the same procedure the Army uses at an official weigh-in:
Pro tip: measure first thing in the morning before eating, and ask someone to check that the tape is level across your back where you cannot see it. Small, consistent technique beats occasional perfection — the same tiny error repeated each time still reveals your true direction of change.
The Army body fat test is the body-composition screening used across the U.S. Army to confirm that Soldiers meet the service's physical readiness requirements. At routine weigh-ins, every Soldier is checked against a screening weight for their height and age. Anyone who exceeds that screening weight is taped: trained personnel take a series of circumference measurements and convert them into a body fat percentage using the official equations published in AR 600-9, the regulation that governs the Army Body Composition Program.
The field procedure is universally known as the tape test. For men, testers record the neck just below the larynx and the abdomen at the navel. For women, testers record the neck, the natural waist, and the hips at their widest point. Each site is measured three times and the readings are averaged, which is why an official test takes a little longer than the quick self-check on this page.
Results are judged against the Army's body fat standards — maximum allowable percentages that vary by age and gender. For the youngest age bracket the ceilings are 20 percent for men and 30 percent for women, rising a few points for older Soldiers. Exceeding the maximum can mean enrollment in the Army Body Composition Program, a structured nutrition and exercise plan with monthly progress checks, and repeated failures can affect promotions, school selection, and retention. The stakes are genuinely high, which is exactly why unofficial practice tools like this calculator are so popular: they let you find out where you stand long before the official tape comes out.
How is this page different from our generic Body Fat Calculator? That tool implements the U.S. Navy circumference method with metric inputs. This page implements the official U.S. Army tape-test formula from AR 600-9 with imperial (inch) inputs — the same equations, units, and measurement sites used at a real Army weigh-in.
Screening only: this calculator estimates body fat from self-reported measurements and cannot produce an official result. It is not a medical device and does not diagnose any health condition. Official Army assessments must be administered by trained personnel using the full AR 600-9 protocol, including repeated measurements with calibrated tapes. Use this tool to practice and prepare — then confirm your standing with your unit's trained testers before any official weigh-in.
The Army's equations are logarithmic regression formulas built from studies of military populations. They estimate body fat from the relationship between your waistline, where fat tends to accumulate, and your height and neck, which reflect your underlying frame size. All measurements are in inches, and log means the base-10 logarithm:
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
Why does the neck measurement matter? Subtracting the neck from the waist (or waist-plus-hip) corrects for frame size and neck musculature, so that a thick neck built from muscle is not misread as abdominal fat. The height term then scales the result to your overall body size. Together, these corrections are what make a simple tape measure surprisingly informative.
Worked example 1 — male Soldier. Height 70 inches, neck 16 inches, waist 34 inches. First, waist minus neck is 34 − 16 = 18; log10(18) = 1.2553, and 86.010 × 1.2553 = 107.97. Next, log10(70) = 1.8451, and 70.041 × 1.8451 = 129.23. Finally, 107.97 − 129.23 + 36.76 = 15.50. The result is 15.5% body fat — comfortably under the 20% Army maximum for most male age groups. These are the calculator's default values, so you can verify the arithmetic yourself by pressing Calculate above.
Worked example 2 — female Soldier. Height 64 inches, neck 13.5 inches, waist 29 inches, hip 38 inches. First, waist + hip − neck = 29 + 38 − 13.5 = 53.5; log10(53.5) = 1.7284, and 163.205 × 1.7284 = 282.07. Next, log10(64) = 1.8062, and 97.684 × 1.8062 = 176.43. Finally, 282.07 − 176.43 − 78.39 = 27.26. The result is 27.3% body fat — under the 30% Army maximum for most female age groups, but close enough that a Soldier in this position would be wise to start training and re-checking well before a weigh-in.
Want to double-check in a spreadsheet? In Excel or Google Sheets the male formula is =86.010*LOG10(waist-neck)-70.041*LOG10(height)+36.76 and the female formula is =163.205*LOG10(waist+hip-neck)-97.684*LOG10(height)-78.387, with each measurement in its own cell in inches.
Numbers on a page become useful when you see them applied. Here are two realistic scenarios showing how Soldiers and veterans use this calculator in practice.
Scenario 1 — SPC Rivera prepares for a weigh-in. Specialist Rivera, 24, is six weeks out from his battalion's semiannual weigh-in. He is 69 inches tall with a 15.5-inch neck, and his waist currently measures 35.5 inches. Running the numbers: waist minus neck is 20, log10(20) = 1.3010, and 86.010 × 1.3010 = 111.90; log10(69) = 1.8389, and 70.041 × 1.8389 = 128.79; 111.90 − 128.79 + 36.76 = 19.87 — about 19.9% body fat, uncomfortably close to the 20% ceiling. Rivera starts running four mornings a week and cleans up his diet. Four weeks later his waist is 34.5 inches, and the same calculation now gives 18.0%. He walks into the weigh-in with a comfortable margin instead of a sleepless week.
Scenario 2 — Maria tracks her post-service fitness. Maria, a 34-year-old Army veteran, wants an objective way to track her recomposition progress without paying for lab tests. She is 65 inches tall with a 13-inch neck, a 30-inch waist, and 39-inch hips. Waist + hip − neck = 56; log10(56) = 1.7482, and 163.205 × 1.7482 = 285.31; log10(65) = 1.8129, and 97.684 × 1.8129 = 177.09; 285.31 − 177.09 − 78.39 = 29.83 — about 29.8% body fat. After twelve weeks of strength training and daily walks, her waist is 28 inches and her hips 37.5, and the recalculation gives 25.3%. The bathroom scale barely moved, but the tape test shows she traded fat for muscle — exactly the kind of progress a plain scale would hide.
Small technique errors can swing your result by several percentage points — enough to turn a pass into a fail. Avoid these five:
Body composition is one piece of the fitness puzzle. Continue exploring with our Body Fat Calculator (U.S. Navy method), BMI Calculator, BMR Calculator, Calorie Calculator, and Ideal Weight Calculator — or browse the full Fitness & Health Calculators collection.
This page provides a free Army Body Fat Calculator implementing the official U.S. Army tape-test body fat equations from AR 600-9 (men: 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76; women: 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387, all measurements in inches). Inputs are gender, height, neck, and waist circumference, plus hip circumference for women. The default male example (70 in height, 16 in neck, 34 in waist) yields 15.5% body fat. Content is for screening and education only, not medical advice; official results require trained AR 600-9 testers.
When measurements are taken carefully, the Army's circumference equations typically land within about 3 to 4 percentage points of laboratory methods like DEXA or hydrostatic weighing. That is accurate enough for screening and tracking trends, which is what the tape test was designed for, but it is not precise enough for clinical diagnosis, and factors like unusual muscularity, bloating, or sloppy tape technique widen the error. Treat your result as a reliable estimate, not a lab-grade measurement.
Under AR 600-9, the maximum allowable body fat for the youngest age bracket (17-20) is 20 percent for men and 30 percent for women, rising by two percentage points per older age group up to 26 percent (men) and 36 percent (women) at age 40 and above. Soldiers who exceed the maximum for their age and gender may be enrolled in the Army Body Composition Program. Because regulations are updated periodically, always confirm the current table in AR 600-9 before an official weigh-in.
Trained testers use a flexible tape on bare skin: for men, the neck just below the larynx and the abdomen at the navel; for women, the neck, the natural waistline, and the hips at their widest point. Each site is measured three times and the readings are averaged before being entered into the AR 600-9 equations. The calculator on this page applies the same formulas to your single set of self-measurements, which is why it is ideal for practice but cannot replace an official test.
Our generic Body Fat Calculator uses the U.S. Navy circumference method with metric (centimeter) inputs, while this page uses the official U.S. Army tape-test formula from AR 600-9 with imperial (inch) inputs — the same units and equations used at an actual Army weigh-in. The two methods usually agree within a point or two, but if you are preparing for an Army assessment, this page's formula is the one that matters.
Absolutely. The equations describe human body geometry, not military status — anyone can enter their measurements and get a valid estimate. Veterans, ROTC cadets, law-enforcement applicants, and general fitness enthusiasts all use the Army tape test as a free, equipment-light way to track body composition. Just remember the result is a screening estimate, not medical advice.
The neck measurement corrects for frame size. Two people with the same waist can carry very different amounts of body fat if one has a thick, muscular neck and broad frame while the other is slightly built. Subtracting the neck (and scaling by height) isolates the abdominal fat the Army actually wants to measure, so muscular Soldiers are not penalized for their build.
Every two to four weeks is ideal for tracking progress — frequent enough to see trends, spaced enough that real change outweighs day-to-day fluctuation. Always measure under identical conditions: same time of day (morning is best), before eating, with the same tape and technique. Daily measurements mostly capture water and digestive noise, not fat change.
First, re-measure carefully — most unexpected results on this calculator turn out to be tape placement or tightness errors (see the mistakes section above). If the number holds, give yourself a realistic runway: a moderate calorie deficit, regular cardio, and strength training two to three times per week reliably move the needle within 6 to 12 weeks. Talk to your unit's master fitness trainer or a registered dietitian for a structured plan, and use this calculator to verify your progress along the way.
APA: SigmaCalculator.net. (2026). Army Body Fat Calculator. https://sigmacalculator.net/fitness-health-calculators/army-body-fat-calculator/
MLA: “Army Body Fat Calculator.” SigmaCalculator.net, 2026, https://sigmacalculator.net/fitness-health-calculators/army-body-fat-calculator/.
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Last updated: October 8, 2026