How to Measure Height, Weight, and Waist for Navy BCA

Equipment and clothing

Official measurements are taken in the Navy PTU or optional PTU. Guide-4 specifies a calibrated scale and a non-stretchable tape, preferably fiberglass. The tape should be checked against a yardstick or metal ruler. Cloth and steel tapes are not the preferred official tools.

Home measurements can help with planning, but they do not become official merely because the same equipment is used.

Height procedure

1. Remove shoes and stand in socks on a flat surface.
2. Stand at attention with the body straight but not rigid.
3. Keep the head horizontal, look forward, and hold the chin parallel to the deck.
4. Measure at the closest part of the scalp; hair must not create artificial height.
5. Record the raw height.
6. Round up to the nearest 0.5 inch for the BCA calculation.

Examples:

“Round up” is not conventional nearest-half rounding. Any amount above a half-inch mark moves to the next half inch.

Weight procedure

1. Use a calibrated balance-beam or digital scale.
2. Wear the authorized PTU/optional PTU, remove shoes, and keep socks on.
3. Record the exact raw weight.
4. Round to the nearest pound: less than 0.5 down; 0.5 or more up.
5. Do not subtract clothing weight.

Weight is collected for every Sailor even when Step 1 passes.

Waist placement

The current Navy waist is measured:

• at the umbilicus or belly button;
• from the right side of the body;
• with the tape horizontal and parallel to the deck;
• on bare skin;
• snug against the skin without compressing soft tissue;
• at the end of a normal respiration;
• while the Sailor stands with feet shoulder-width apart, arms down, and head forward.

This is not a “smallest waist” measurement. It is also not the hip or neck measurement used in older circumference methods.

Two readings and the third-reading rule

Each waist measurement is taken twice, and each reading rounds down to the nearest half inch. If the two rounded readings differ by more than 1 inch, take another reading. Use the two closest rounded values, average them, and round the average down to the nearest half inch.

Guide-4 example:

The closest rounded pair is 32.5 and 32.0. Their average is 32.25, which records as 32.0 after rounding down to the nearest half inch.

Waist rounding examples

The calculator should use a floor-to-half-inch operation, not round(value × 2) ÷ 2.

Why measurement error matters

A half-inch change can move a Sailor across the Step 1 boundary or to a different Step 2 row. Common sources of variation include tape angle, tissue compression, a held breath, inconsistent placement, and pre-rounding.

For repeatable personal tracking:

• use the same tape and procedure each time;
• record the raw values before any conversion;
• avoid pulling the tape tighter to chase a result;
• never use dehydration or other extreme short-term methods to alter the measurement.

Guide-4 warns that dehydration is dangerous and describes consequences for attempted alteration of official measurements.

From recorded measurements to result

After recording the values:

1. Divide recorded waist by recorded height.
2. Round down to four decimals.
3. If the result is 0.5499 or less, Step 1 is within standards.
4. Otherwise use recorded weight and height-minus-waist difference in the official Step 2 table.

See the maximum-waist chart and Step 2 guide for those calculations.

Frequently asked questions

Sources and review

Procedure checked against MyNavyHR Guide-4, Section 2 on September 10, 2026.

CalculatorGeek is not affiliated with the U.S. Navy. This guide does not replace an official CFL/ACFL measurement.