Army Body Fat Calculator

Height

Estimated Body Fat

15.5%

Body Fat CategoryFitness

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Includes your inputs and results for this calculation, plus any additional calculations you've compared.

Good to Know

This is a circumference-based estimate, not a direct measurement — it can be less accurate for people with body types that fall outside the population the formula was originally validated on, including very muscular or very lean individuals. Measurement technique also affects the result meaningfully.

Disclaimer

This calculator provides estimates for informational purposes only and does not constitute financial, medical, legal, or tax advice. Always consult a qualified professional about your specific situation.

How This Calculator Works

The Army Body Fat Calculator estimates body fat percentage from simple tape-measure circumferences, using the formula specified in AR 600-9, the U.S. Army’s body composition standard. Enter your gender at birth, height, neck, and abdomen (or waist) measurements — plus hip measurement if using the female formula — and this calculator estimates your body fat percentage and which standard category it falls into.

This is a genuinely different formula from the U.S. Navy Circumference Method used by this site’s other Body Fat Percentage Calculator — both estimate the same thing from the same kind of tape-measure inputs, but were developed and published independently, and don’t always agree exactly. If you have a DA Form 5500 or 5501 fitness record, this is the formula it was calculated with.

The Formula

Men:

Body Fat %=86.010×log10(AbdomenNeck)70.041×log10(Height)+36.76\text{Body Fat \%} = 86.010 \times \log_{10}(\vA{\text{Abdomen}} - \vB{\text{Neck}}) - 70.041 \times \log_{10}(\vD{\text{Height}}) + 36.76

Women:

Body Fat %=163.205×log10(Waist+HipNeck)97.684×log10(Height)78.387\text{Body Fat \%} = 163.205 \times \log_{10}(\vA{\text{Waist}} + \vC{\text{Hip}} - \vB{\text{Neck}}) - 97.684 \times \log_{10}(\vD{\text{Height}}) - 78.387

All measurements use the same unit (inches, in the formula’s original published form — this calculator converts automatically regardless of which unit you enter in). Abdomen/waist is measured at the navel; neck just below the larynx; hip at its widest point (women’s formula only).

The result is compared against the same American Council on Exercise (ACE) categories this site’s Navy-method calculator already uses — Essential Fat, Athletes, Fitness, Average, and Obese — so a given percentage lands in the same category regardless of which formula produced it.

Worked Example

A male, height 70in (177.8cm), neck 16in (40.64cm), abdomen 34in (86.36cm):

  1. Abdomen minus neck: 3416=18\vA{34} - \vB{16} = 18, and log10(18)1.2553\log_{10}(18) \approx 1.2553.
  2. 86.010×1.2553107.9786.010 \times 1.2553 \approx 107.97.
  3. log10(70)1.8451\log_{10}(\vD{70}) \approx 1.8451, and 70.041×1.8451129.2570.041 \times 1.8451 \approx 129.25.
  4. 107.97129.25+36.7615.5%107.97 - 129.25 + 36.76 \approx 15.5\%.

An estimated body fat of about 15.5% falls in the Fitness category for men (14-17%).

Source: U.S. Army Body Composition Program (AR 600-9).

Frequently Asked Questions

How is this different from the U.S. Navy body fat method?

Both estimate body fat percentage from tape-measure circumferences, but they use independently-developed formulas that don't always agree exactly. This calculator uses the U.S. Army's own AR 600-9 formula — if you have a DA Form 5500/5501 fitness record, this matches the calculation it was based on.

Where exactly should I measure?

Neck: just below the larynx (Adam's apple), tape sloped slightly downward at the front. Abdomen/waist: at the navel, standing relaxed (not sucked in). Hip (women's formula only): at the widest point around the hips and buttocks. Measure snugly but without compressing the skin.

Why does the formula differ between men and women?

Fat distribution differs between men and women, so the Army method (like the Navy method) uses a different formula and includes a hip measurement for women that isn't needed for men.