With a scale, a way to measure height, and CDC’s adult BMI calculator, it’s hard to get a BMI calculation wrong.īut using BMI has some limitations. BMI is an accepted and reliable way to assess body composition. Body mass index (BMI) is a tool to quickly categorize someone as underweight, healthy weight, overweight, or obese, based on their height and weight. The weight standards used by the military, as set by DoDI 1308.03, are a close approximation of BMI. DoDI 1308.03 states: “Body composition may be evaluated using either BF (body fat) calculations, waist-to-height ratio, abdominal circumference, height-weight screening, or any combination thereof.” Body mass index The DoDI sets the standard but allows each Service to choose which method they use to measure body composition. For military use, measurement methods also need to be easy to learn without special expertise, since most Service Members doing the assessments aren’t medical providers or fitness experts. Practical body-composition assessments simply need be valid and reliable, which means they measure what they’re intended to measure with reasonable accuracy and their measurements are consistent. Advanced imaging is expensive and time-consuming, so it’s rarely used for body-fat assessments outside of research settings.

The only ways to measure the exact amounts of body fat and the various types of lean body mass are direct measurement after death or advanced imaging. Body composition basicsīody compositioncan be estimated in many different ways, each with its own pros and cons. All Service Members are still required to have a body composition assessment at least once per year-and expected to meet these standards to maintain operational readiness, successfully perform their duties, and reduce the risk for injuries and obesity-related diseases. In the example, 70.14 divided by 220 times 100 calculates a percent body fat of 31.88 percent.The DoD Instruction about physical fitness and body composition requirements for Service Members was updated in 2022, and DoDI 1308.03 outlines the latest rules. Multiply by 100 to calculate percent body fat. In the example, this formula calculates fat mass as follows:įat Mass = 220 - Fat Mass = 220 - 149.86 Fat Mass = 70.14ĭivide your fat mass by your body weight. Wrap a tape measure around your waist and record the amount for example, 44 inches.Įnter the results in the following formula to calculate fat mass: Weigh yourself on a weight scale and record the result for example, 220 pounds.

In the example, 36.07 divided by 140 times 100 calculates a percent body fat of 25.76 percent. In the example, the formula would break down as follows:įat Mass = 140 - Fat Mass = 140 - Fat Mass = 140 - 103.93 Fat Mass = 36.07ĭivide your fat mass by your body weight and multiply by 100 to calculate percent body fat. Measure around your forearm at the fullest point and record that number for example, 10 inches.Įnter your measurements in the following formula to calculate fat mass:įat Mass = Weight. Measure around your hips at the widest point and record the result for example, 38 inches. Wrap the tape measure around your waist, level with your navel and record the result for example, 28 inches.

Body fat measurement tape