Army Body Fat Calculator
Estimate body fat percentage using the historical US Army tape-test (circumference) method, compared against the pre-2026 AR 600-9 age-band standards and general body-fat categories.
Historical AR 600-9 Body Fat Standards (Pre-July 2026)
These age-band maximums applied under the tape-test system used before 7 July 2026. The Army has since replaced this entirely with a waist-to-height ratio standard that does not use a body-fat percentage — these figures are shown for historical context only, not as a current requirement.
General Body Fat Categories
A commonly used reference (based on American Council on Exercise categories), independent of the Army standard above.
Army Body Fat Calculator
Our Army Body Fat Calculator estimates body fat percentage using the historical US Army circumference-based “tape test” method, previously set out in Army Regulation 600-9 (AR 600-9). It requires only a tape measure — height, neck and waist for men, plus hip for women — making it usable without any specialist equipment. As of 7 July 2026, the US Army no longer uses this method or a body-fat percentage at all: Army Directive 2026-13 replaced it with a waist-to-height ratio (WHtR) standard of less than 0.55, with no age or sex adjustment. This tool is offered as a general body-composition estimator using the historical formula, for anyone still interested in it; it is not an official UK Armed Forces assessment and has no bearing on actual military service or enlistment decisions.
How the Tape Test Formula Works
The AR 600-9 circumference method uses these formulas (all measurements 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
This calculator accepts measurements in centimetres or inches and converts internally, since the original formula is defined in inches. Correct measurement technique matters for accuracy:
- Neck: measured just below the larynx (Adam’s apple), tape sloping slightly downward at the front.
- Waist (men): measured at the navel, at the end of a normal breath.
- Waist (women): measured at the narrowest point of the torso.
- Hip (women): measured at the widest point of the buttocks.
Historical AR 600-9 Body Fat Standards (Pre-July 2026)
Until 7 July 2026, the Army set a maximum allowable body fat percentage by age band as part of its body composition program, applied when a soldier exceeded a height/weight screening table. Commonly cited figures under that system were:
| Age Band | Male Maximum | Female Maximum |
|---|---|---|
| 17–20 | 20% | 30% |
| 21–27 | 22% | 32% |
| 28–39 | 24% | 34% |
| 40+ | 26% | 36% |
These figures reflect the AR 600-9 body composition standards that applied before 7 July 2026. Under Army Directive 2026-13, the Army now uses a waist-to-height ratio standard (below 0.55, waist measured at the navel, divided by height) instead — with no body-fat percentage, no age bands, and the same threshold for all soldiers regardless of sex. These historical figures have no current effect; they’re shown for reference only.
How Accurate Was the Tape Test?
The circumference method’s standard error compared with laboratory methods like DEXA or hydrostatic weighing is commonly cited as roughly 3 to 4 percentage points, though some more recent research puts it closer to 2 to 3 percentage points — estimates vary by study and population. It tended to be reasonably reliable for people with an average body shape, but was less accurate for people with an above-average amount of muscle (who could be overestimated) or an unusual distribution of body fat, since it relies on a small number of circumference measurements rather than a full-body assessment. This is part of why the Army moved away from it in 2026.
Frequently Asked Questions
Is this an official military body fat test?
No — and beyond that, this method is no longer used by the Army at all. This calculator uses the formula previously published in AR 600-9, but as of 7 July 2026 the Army replaced the tape test and its body-fat standards with a waist-to-height ratio (WHtR) standard under Army Directive 2026-13. Even when the tape test was current, official Army measurements were taken by trained personnel following specific protocols, and only counted when administered as part of the actual Army Body Composition Program. This tool is for general informational purposes only, using a historical formula, and results here have no bearing on real enlistment, service or compliance decisions. It is also not a UK Armed Forces standard.
How accurate is the Army tape test method?
Its standard error compared with lab methods like DEXA is commonly cited as around 3 to 4 percentage points, though some more recent research puts it closer to 2 to 3 — estimates vary by study. It was a reasonable field estimate for people with an average body composition, but could be less accurate for very muscular individuals (who tended to be overestimated) or people with an unusual fat distribution. Note that as of July 2026 the Army no longer uses this method.
Why do I need my hip measurement if I’m male?
You don’t — the male formula only uses neck, waist and height. Hip circumference is only used in the female formula, which reflects that body fat distribution patterns typically differ between men and women.
What if my waist measurement is smaller than my neck?
The formula can’t produce a result in that case, since it takes a logarithm of (waist minus neck) for men, or (waist plus hip minus neck) for women — this needs to be a positive number. For most adults this isn’t an issue, but if you see an error, double-check your measurements and make sure you’ve selected the correct units.
How do the AR 600-9 standards compare to general body fat categories?
They’re two different reference points. The historical AR 600-9 limits (used before July 2026) were administrative maximums within the US Army’s body composition program, not a health-optimised target. The general body fat categories shown alongside them (based on American Council on Exercise reference ranges) reflect broader fitness classifications and aren’t tied to any military standard, current or historical.
Does this apply to UK Armed Forces personnel?
No. This calculator uses the US Army’s published formula and standards as a general body-fat estimation method available to anyone. UK Armed Forces personnel are assessed under separate British Ministry of Defence standards, which are not what this tool calculates.