🎖️ Army Body Fat Calculator
By ToolNimba Health Team · Reviewed by ToolNimba Editorial Review, fitness and body composition content · Updated 2026-06-19
This calculator estimates body fat from tape measurements and is for general information only, it is not an official Army assessment and is not medical advice. Real AR 600-9 readings are taken by a trained measurer to a set protocol, and standards are updated by the Army periodically. For an official result or any health decision, rely on a qualified professional and the current regulation, not this estimate.
This Army body fat calculator uses the US Army circumference (tape test) method from regulation AR 600-9 to estimate your body fat percentage from a few tape measurements. Choose your sex, enter your height, neck and waist (plus hip for women), and add your age to see whether your estimate falls within the Army maximum for your group. It runs entirely in your browser, with inches by default and an optional centimeters mode.
What is the Army Body Fat Calculator?
The US Army uses a circumference-based body fat estimate, often called the tape test, when a soldier exceeds the screening weight for their height. Rather than calipers or a scan, a measurer wraps a tape at set landmarks and feeds those numbers into a formula. The Army method shares the same log10 equations as the well-known US Navy method, so the percentages the two produce are essentially identical for the same measurements.
For men the estimate uses just the waist and neck against height: body fat % = 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76, with every length in inches. For women the hip is added because hip circumference carries useful information about fat distribution: body fat % = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387. The subtraction of neck from waist (and hip) isolates the fat-bearing girth from frame size, and dividing by height scales it to body length.
The second half of the assessment is the standard itself. AR 600-9 sets a maximum allowable body fat that rises with age, because body fat naturally increases over the years, and the limits differ by sex. A soldier who passes the height and weight screen never needs the tape test, and a soldier who exceeds the screen but comes in under the body fat limit still meets the standard. This tool reproduces both halves: it estimates the percentage and compares it to the age and sex limit so you can see where you stand before an official measurement.
When to use it
- Estimating your body fat before an official Army height, weight and tape assessment so there are no surprises.
- Checking whether your current measurements fall under the AR 600-9 maximum for your age and sex.
- Tracking circumference changes over a training cycle using a consistent, repeatable method.
- Comparing the Army tape-test estimate with a Navy-method result, since both use the same equations.
How to use the Army Body Fat Calculator
- Pick your sex, since the formula and the allowable limit differ for men and women.
- Enter your age so the result can be checked against the right AR 600-9 limit.
- Measure your height, neck and waist (women also measure the hip) and enter them in inches, or switch to centimeters.
- Read your estimated body fat percentage and whether it is at or below the Army maximum for your group.
Formula & method
Worked examples
A 25-year-old man: waist 34 in, neck 16 in, height 70 in.
- waist - neck = 34 - 16 = 18, and log10(18) = 1.255273
- 86.010 x 1.255273 = 107.966
- log10(70) = 1.845098, so 70.041 x 1.845098 = 129.2325
- body fat = 107.966 - 129.2325 + 36.76 = 15.49
- Rounded: about 15.5% body fat
- AR 600-9 limit for a man aged 21 to 27 is 22%, so 15.5% is within standard.
Result: About 15.5% body fat, within the 22% limit for his age and sex.
A 30-year-old woman: waist 30 in, hip 40 in, neck 13 in, height 64 in.
- waist + hip - neck = 30 + 40 - 13 = 57, and log10(57) = 1.755875
- 163.205 x 1.755875 = 286.5676
- log10(64) = 1.806180, so 97.684 x 1.806180 = 176.4349
- body fat = 286.5676 - 176.4349 - 78.387 = 31.75
- Rounded: about 31.7% body fat
- AR 600-9 limit for a woman aged 28 to 39 is 34%, so 31.7% is within standard.
Result: About 31.7% body fat, within the 34% limit for her age and sex.
AR 600-9 maximum allowable body fat percentage by age and sex
| Age band | Men (max %) | Women (max %) |
|---|---|---|
| 17 to 20 | 20% | 30% |
| 21 to 27 | 22% | 32% |
| 28 to 39 | 24% | 34% |
| 40 and over | 26% | 36% |
Where to place the tape for each measurement
| Measurement | Where to measure |
|---|---|
| Neck | Just below the larynx (Adam’s apple), tape sloping slightly down at the front |
| Waist (men) | At the navel, level all the way around, taken at the end of a normal breath out |
| Waist (women) | At the smallest point of the abdomen, usually above the navel |
| Hip (women) | At the widest point of the hips and buttocks, tape level all around |
| Height | Standing straight without shoes, measured to the nearest quarter inch |
Common mistakes to avoid
- Pulling the tape too tight. A tape that compresses the skin reads smaller than your true girth and understates body fat. The tape should be snug and level, touching the skin without indenting it. Measuring loosely overstates the result the other way.
- Measuring the waist at the wrong spot. For men the Army waist is at the navel, not the narrowest point, and for women it is at the smallest point of the abdomen. Using the belt line or the narrowest part for a man can shift the estimate by several points.
- Forgetting the hip measurement for women. The female formula needs waist, hip and neck. Leaving the hip out, or using the male formula, will give a wrong and usually much lower number. This tool shows the hip field only when sex is set to female.
- Treating the estimate as an official score. A tape test done at home is a useful guide, but the official AR 600-9 result is taken by a trained measurer to an exact protocol, often averaging several readings. Use this estimate to prepare, not to predict the exact number on the day.
Glossary
- AR 600-9
- The US Army regulation, The Army Body Composition Program, that sets weight screening tables, the tape-test method and the maximum allowable body fat by age and sex.
- Tape test
- The circumference method of estimating body fat using a tape measure at set body landmarks, used when a soldier exceeds the screening weight.
- Circumference method
- Any body fat estimate based on the girth of body parts (neck, waist, hip) rather than calipers, scans or water displacement.
- Screening weight
- The maximum weight for a soldier’s height and age, a soldier under it passes without a tape test.
- Body fat percentage
- The share of total body mass that is fat tissue, the figure the Army compares against its allowable limits.
Frequently asked questions
How does the Army calculate body fat?
The Army uses the circumference, or tape test, method from AR 600-9. A measurer records neck and waist for men, and neck, waist and hip for women, along with height, then puts them into a log10 formula. The result is an estimated body fat percentage that is compared against the maximum allowed for the soldier’s age and sex.
Is the Army formula the same as the Navy method?
Yes, the Army circumference method uses the same log10 equations as the US Navy method, so for identical measurements the two give essentially the same body fat percentage. What differs is the standards: the Army and Navy each set their own maximum allowable percentages by age and sex.
What is the maximum body fat allowed in the Army?
Under AR 600-9 the limit rises with age. For men it is 20% (17 to 20), 22% (21 to 27), 24% (28 to 39) and 26% (40 and over). For women it is 30%, 32%, 34% and 36% across the same age bands. This tool flags whether your estimate is at or below the limit for your group.
Where do I measure my waist and neck?
Measure the neck just below the larynx with the tape sloping slightly downward at the front. For men measure the waist at the navel, and for women at the smallest point of the abdomen. Keep the tape level and snug, and take the reading at the end of a normal breath out.
Do I have to take the tape test?
No. The tape test only applies if a soldier exceeds the screening weight for their height and age. If you pass the height and weight screen you meet the standard without any body fat measurement. If you exceed the screen but come in under the body fat limit, you still meet the standard.
Is this calculator accurate enough for my real assessment?
It uses the official AR 600-9 equations, so the math matches, but home measurements vary with tape placement and tension. An official assessment is taken by a trained measurer following an exact protocol, often averaging multiple readings. Use this as a preparation guide rather than a guaranteed score.
Sources
- AR 600-9, The Army Body Composition Program , U.S. Army Publishing Directorate
- Body Fat Measurement: Percentage vs. Body Mass , American Council on Exercise