How to Count BMI
In addition to your waist circumference, your body mass index, or BMI, is often used by health care providers to assess whether you're at a healthy weight for your height. To determine your BMI, some counting and calculating is required, but knowing where you are can help you decide whether you should lose, gain or maintain your weight. Since excess fat around your waistline is associated with health conditions such as stroke, diabetes, heart disease and high blood pressure, determining your BMI can put you one step ahead of the game.
Determine your weight in pounds and write down this number. Place your scale on a hard-floor surface, strip down to your underwear and weigh yourself barefoot to get a fair indication of your weight.
Multiply your weight -- for this example, let's say you're 5 feet 8 inches tall and 150 pounds -- by 703 with a calculator. One-hundred fifty pounds multiplied by 703 equals 105,450. Record this number.
Use a measuring tape to determine your height in inches. Alternatively, have a friend measure you. For this example, a person who's 5 feet 8 inches is 68 inches tall.
Divide your result from Step 2 by your height in inches. In this case, 105,450 divided by 68 equals 1550.7.
Divide your result from Step 4 by your height in inches again to determine your BMI. For this example, 1550.7 divided by 68 equals 22.8. Record your BMI for future reference.
Check to see which category your BMI falls in. A BMI that's below 18.5 is considered underweight, a BMI from 18.5 to 24.9 is considered healthy, a BMI from 25.0 to 29.9 is considered overweight, a BMI from 30.0 to 39.9 is considered obese and a BMI over 40 is considered extremely obese.
- If you're muscular, determine your body fat by measuring your waist circumference because your BMI might seem high even though you're healthy. This is because muscle tissue is denser than fat. If you're a man, aim for a waist circumference of less than 40 inches, and if you're a woman, a circumference of less than 35 inches is healthy.
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