Navy body fat calculator for the 2026 Body Composition Assessment (BCA)

The Navy dropped the neck and hip measurements

Guide-4 collects three measurements from every Sailor: height, waist at the belly button, and weight. There is no neck measurement and no hip measurement. The Navy's own guide prints tables and no body fat equation.

Many calculators online still ask for neck and hip and run an older circumference formula, often called the Navy method or the US Navy body fat percentage formula. That formula does not decide a Navy result today. If you want it as a general fitness estimate, you will not find it here, because the Navy's own guide no longer uses it.

Step 1: waist-to-height ratio

Divide the recorded waist by the recorded height. Cut the answer to four decimals, which means dropping the extra digits and never rounding up. Men and women use the same rule.

A ratio of 0.5499 or lower is within standards and the assessment ends there. A ratio of 0.5500 or higher goes to Step 2.

Table-1 turns the rule into a largest waist for each height, in half inch steps from 48 to 83.5 inches. All 72 rows of Table-1 agree with that rule. The ratio column in Table-1 is rounded to the nearest fourth decimal, so the row for 66.5 inches prints 0.5489 while the cut value is 0.5488. The pass or fail result is the same.

Step 2: body fat from the tables

Subtract the waist from the height. Find the column for your weight in pounds and the row for that difference. The number in the cell is your estimated body fat percent. Table-2 is for men and Table-3 is for women.

The limit is 26 percent for men and 36 percent for women, with no age bands. A man at 26 percent is within standards, and 27 percent is not. A woman at 36 percent is within standards, and 37 percent is not.

Two worked examples

A man is 70 inches tall, has a 40 inch waist and weighs 190 pounds. His ratio is 0.5714, over the 38 inch largest waist for his height, so he goes to Step 2. Height minus waist is 30. Table-2 gives 24 percent at 190 pounds, which is under the limit of 26. He is within standards.

A woman is 65 inches tall and has a 38 inch waist. Her ratio is 0.5846 and the largest waist for her height is 35.5 inches. Height minus waist is 27. At 181 pounds Table-3 gives 36 percent, which is within standards. At 182 pounds it gives 37 percent, which is not.

What the tables cover

Table-2 covers men from 101 to 380 pounds and Table-3 covers women from 61 to 300 pounds. Each page shows a window of height-waist differences that moves with weight. Printed values run from 16 to 28 percent for men and from 24 to 38 percent for women.

When your weight or your height-waist difference falls outside the printed table, Guide-4 says to record the raw measurements, and the Navy's system calculates the official body fat from them. This calculator says the printed tables do not cover the case and does not estimate a number.

Measuring height, waist and weight

Guide-4 measures height with shoes off and socks on, standing at attention with the head level. Weight is taken in the physical training uniform on a calibrated scale, with no deduction for clothing.

The waist is measured at the belly button from the right side, with the tape parallel to the deck, on bare skin. The tape is snug but not compressing. You stand with feet shoulder-width apart and arms down, and the reading is taken at the end of a normal breath out.

Rounding the waist

Every waist reading is taken twice and rounded down to the half inch. If the two differ by more than one inch, a third is taken and the two closest are averaged and rounded down. Guide-4 works one example. Readings of 34.25, 32.5 and 32.25 round down to 34, 32.5 and 32. The first two are 1.5 inches apart, so the third counts. The two closest are 32.5 and 32, which average 32.25 and record as 32 inches.

The tape readings box in the calculator follows that procedure. If the first two readings are within one inch, it records their average rounded down.

Rounding height and weight

Guide-4 says height measurements "will be rounded up to nearest ½ inch". That can mean always up to the next half inch or to the nearest half inch, so the calculator asks for the height as it was recorded to the half inch. Weight goes to the nearest pound: under half a pound rounds down and half a pound or more rounds up.

After a result that is not within standards

A Sailor who is not within standards at both steps still takes the PRT, with medical clearance first. The official body composition assessment is final, and Guide-4 allows no retest. A body composition failure is a fitness assessment failure unless the Sailor qualifies for the high-performance exemption, which needs a strong PRT. Use the Navy PRT calculator to see where a set of PRT results lands.

Points the body composition guide does not settle

Guide-4 does not say which way to read "rounded up to nearest ½ inch" for height. It defines an average of readings only for the three-reading case, so the two-reading case here is a reading of this calculator. It does not say what to do when two pairs of readings are equally close, or when no two readings are within one inch. The calculator stops and says so in both cases.

Table-1 prints heights from 48 to 83.5 inches. For other heights the ratio rule still decides Step 1, and the calculator shows no printed largest waist.