The Importance of Accurate Measurements

The U.S. Navy Method is a fantastic, free way to estimate your body fat percentage at home. However, because it relies entirely on the measurements you provide, the accuracy of the result is directly tied to the accuracy of your measuring technique.

Here is a step-by-step guide to getting it right.

What You Need

• A flexible, non-stretch fiberglass or cloth measuring tape. (Do not use a metal construction tape).
• A mirror (to ensure the tape is level).
• Preferably, a friend or partner to help, though you can do it alone.

General Rules

1. Measure in the morning: Take your measurements right after waking up and using the restroom, before eating or drinking. This minimizes fluctuations caused by bloating or hydration.
2. Keep it level: The tape must be perfectly horizontal around your body. Check the mirror to ensure it isn't sagging in the back.
3. Skin contact: The tape should rest firmly against your skin but should not compress the tissue. Do not pull it tight enough to create an indentation.
4. Breathe normally: Do not suck in your stomach or puff out your chest. Take the measurement at the end of a normal exhale.

How to Measure

1. Height

Stand straight against a wall without shoes. Keep your heels, buttocks, shoulders, and head touching the wall. Look straight ahead.

2. Neck

Look straight ahead with your shoulders relaxed. Place the tape measure around your neck, just below your larynx (Adam's apple). Ensure the tape is horizontal and resting lightly on the skin.

3. Waist (Men)

Measure horizontally around your abdomen at the level of your navel (belly button).

4. Waist (Women)

Measure horizontally around your abdomen at the narrowest point, usually halfway between the bottom of your ribs and the top of your hip bones.

5. Hips (Women Only)

Stand with your feet together. Measure horizontally around the largest circumference of your hips and buttocks.

Consistency is Key

Even if your measurements are slightly off from clinical perfection, as long as you measure exactly the same way every time, the trend will be accurate. If the calculator says you dropped from 25% to 23%, you have successfully lost fat, regardless of whether the absolute number is perfectly precise.