Army Body Fat Calculator

The Army no longer tapes for body fat. Since July 7, 2026 its body composition standard has been a waist-to-height ratio: the waist measured at the navel, divided by height, both in inches. Under 0.55 passes.

A Soldier at 0.55 or over is measured again by a second team the same duty day. If that confirms it, the Soldier is flagged and enrolled in the Army Body Composition Program (ABCP) until they meet the standard. Everyone is assessed twice a year.

The change follows a Pentagon memorandum dated December 18, 2025, which set the same ceiling, a ratio under 0.55, for every service from January 1, 2026. The Army was the last service to adopt it. It began a 180-day assessment period at the same time, with no separations for failing the new test during it.

The formula:

Ratio = Waist at the navel ÷ Height

Worked example: a Soldier 70 inches tall with a 37-inch waist.
37 ÷ 70 = 0.529, a pass.
The line at that height sits at 0.55 × 70 = 38.5 inches, so the waist has 1.5 inches in hand.

The ratio moves by 1 ÷ height for every inch of waist: about 0.014 at 70 inches. That is why a careless half inch at the tape matters more than it looks.

What it replaced

The height and weight tables, and the tape test that backed them up. For decades that tape test was the Department of Defense circumference method, from the equations James Hodgdon and Marcie Beckett fitted at the Naval Health Research Center in 1984. All measurements in inches:

Men: Body Fat % = 86.010 × log₁₀(abdomen − neck) − 70.041 × log₁₀(height) + 36.76

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

In 2023 the Army moved to a one-site tape test, the abdomen plus body weight, and from June 2024 that was the only method allowed, until the waist-to-height ratio replaced it.

This page still works out the old circumference estimate. It is a reasonable body fat figure from a tape measure, which is a different question from whether you pass, and it is the number most people remember from being taped. It also shows the age-banded maximums that went with it, which no longer decide anything:

Worked example (male, old formula):

Height 70 inches, waist at the navel 34 inches, neck 15.5 inches.

Body Fat = 86.010 × log₁₀(34 − 15.5) − 70.041 × log₁₀(70) + 36.76
= 86.010 × 1.26717 − 70.041 × 1.84510 + 36.76
= 108.99 − 129.23 + 36.76
= 16.5%

The same man’s ratio is 34 ÷ 70 = 0.486, comfortably under 0.55.

How to measure:

• Waist (the ratio, and the old male formula): at the navel, horizontal, against the skin, at the end of a normal breath out.
• Neck (old formula only): just below the larynx (Adam’s apple), perpendicular to the long axis of the neck.
• Narrowest waist (old women’s formula only): the old method measured a woman’s waist at its narrowest, not at the navel. Leave that box blank and the page uses the navel figure, which reads a little high.
• Hip (old women’s formula only): at the widest point of the buttocks, parallel to the floor.
• Height: without shoes, feet together.

The circumference difference drove the old answer

Only one number in the male formula does real work: waist minus neck. Height enters as a correction, and everything else is a constant. Add an inch to the waist and the result moves about 2 percentage points at typical dimensions.

That was also its weakness. It could not tell a thick neck built by training from a thick neck built any other way, so it flattered people with heavy necks. The ratio has a blind spot of its own: it cannot see a neck at all, so a thick, muscular trunk can count against you.

Accuracy note: the old formula sits roughly 3 to 4 percentage points away from a DEXA scan, in either direction. Neither it nor the ratio measures fat directly.
Every service writes its own instruction around the Pentagon ceiling, so if you are being measured for record, the current Army Regulation 600-9 and your unit’s guidance decide, not this page.