Body Mass Index (BMI)

BMI stands for Body Mass Index. It is a measure of body composition. The higher the figure the more overweight you are. Like any of these types of measures it is only a guide, and other issues such as body type and shape have a bearing as well. Remember, BMI is just a guide - it does not accurately apply to elderly populations, pregnant women or very muscular athletes such as weight lifters.



Calculate your own BMI !

BMI is calculated by taking a person's weight and dividing by their height squared. The standard is to use metric units. For instance, if your height is 1.82 meters, the divisor of the calculation will be (1.82 * 1.82) = 3.3124. If your weight is 70.5 kilograms, then your BMI is 21.3 (70.5 / 3.3124). Using pounds and inches, BMI can be calculated by multiplying by a conversion factor of 703, so BMI = weight (lb) / [height (in)]2  x 703

It is easier if you use these calculators.

Test Details

equipment required: scales and stadiometer required for measuring weight and height.

procedure: BMI is calculated from body mass (M) and height (H). BMI = M / (H x H), where M = body mass in kilograms and H = height in meters. The higher the score usually indicating higher levels of body fat.

scoring: Generally, a BMI between 20 and 25 is considered normal weight for height, and outside these values is either underweight or overweight. The rating scale is the same for males and females. See the table of BMI Norms based on the World Health Organization BMI classification system. You can also use the reverse lookup BMI table for determining your ideal weight based on height.

target population: BMI is often used as a general population measure to determine the level of health risk associated with obesity.

advantages: only simple calculations are required from standard height and weight measurements.

disadvantages: in certain populations BMI can be inaccurate as a measure of body fatness, for example large and muscular though lean athletes may score high BMI levels which incorrectly rates them as obese.

other comments: Other simple measures of body composition, such as skinfolds measures, would be preferable if available.



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