How to Calculate BMI for Athletes

Overview

When it comes to athletes, there are many assessments used to determine their health status. Some of these include body weight, body fat percentage, lean muscle mass and BMI, also called body mass index. Body mass index is the amount of fat an individual has in relation to his height and weight. Medical and fitness professionals use this as a quick reference when they are analyzing athletes. To determine BMI, input a couple numbers into an equation.

Step 1

Determine your weight. The best time to weigh yourself is first thing in the morning on an empty stomach right after getting out of bed and after using the bathroom. To make it even more precise, weigh yourself in your underwear or with no clothes on at all.

Step 2

Measure your height. Stand with your back to a wall or stand inside an open doorway. Take a pencil and place a tick mark on the wall at the top of your head. Get out a tape measure and determine your height in inches.

Step 3

Find your body mass index. The equation for BMI is 703 times your weight divided by your height squared. Here's an example using a female athlete that is 5-foot-8 and weighs 140 pounds: (703 x 140) / (68 x 68) = a BMI of 21.28.

Step 4

Determine BMI using the metric system. In the case of the metric system, divide your weight in kilograms by your height in meters squared. To convert weight to kilograms, divide it by 2.2 and to convert height to meters, multiply your height by .0254, as this is the amount of meters in one inch. Here's an example using a male athlete that is 6-foot-6 and weighs 220 pounds:

220 / 2.2 = 110kg
78 x .0254 = 1.98

110 / (1.98 x 1.98) = a BMI of 28.06.

Step 5

Look it up online. If you have access to a computer, you can find your BMI quickly with an online calculator. The Centers for Disease Control has one of these available (see References). Just input your height and weight and your BMI comes up in a matter of seconds.

Step 6

See what range you land in. If you are less than18.5, you are considered underweight. If you are in the range of 18.5 to 24.9, you are considered normal; 25 to 29.9 is considered overweight and anything above 30 is considered obese (see References for chart).