Easy Ways to Measure BMI

Body mass index, or BMI, serves as a tool to evaluate health. The formula takes a person's height and weight and produces a number, typically between 15 and 40. A number between 18 and 25 is considered healthy, with any result below 18 considered underweight and any score about 25 considered overweight. A BMI of more than 30 is considered obese.

Calculators

• Many websites offer a BMI calculator where you enter your height and weight. If you plug in age and gender, many calculators also provide information such as your basal metabolic rate, or BMR. If you provide your normal activity level, such as sedentary or active, some calculators even provide an estimate of how many calories you should consume a day. See the Resources section for suggested calculators.

The Formula

• If you wish to perform the BMI calculation yourself, simply use the BMI formula. First, multiply your weight in pounds by 703. Then, square your height in inches. Divide the first number by the second number to find your BMI.

  To find this number using metric measurements, divide your weight in kilograms by your height in meters squared.

Charts

• Many websites provide BMI charts. You can also find these at your doctor's office or at many gyms or health food stores. Some scales even come with a BMI chart. To determine your BMI from a chart, simply find the place where your height and weight intersect. Since BMI charts use set increments, your number will be less accurate than if you use a calculator.

Considerations

• BMI is only one component of measuring health and cannot provide a complete picture. If your BMI is very high or very low, you should talk to a doctor. However, people who are very fit, such as body builders and athletes, may register a very high BMI despite low body fat. Try to estimate your body fat before jumping to conclusions about BMI.