What Is The Bmi For Height & Weight?

Body mass index, or BMI, is a method for assessing body composition. The BMI is a fairly reliable indicator of your risk level for diseases associated with obesity. The BMI is preferred over skinfold calipers as a measure of body fat because of its difficulty in obtaining consistent results and lack of a standardized formula, say exercise physiologists Thomas R. Baechle and Roger W. Earle, in their book "Essentials of Strength Training and Conditioning."

BMI Formula

BMI is calculated by dividing your weight in kilograms by your height in meters, squared. To obtain your BMI using pounds and inches, divide your weight in pounds by your height in inches, squared, and multiply this by the number 703. You can also enter your information into an online BMI calculator.

Classifications

For adults, a BMI between 18.5 and 24.9 is said to be a normal body composition. A BMI reading of less than 18.5 is considered underweight, and a measure of 25 to 29.9 is considered overweight. Measures of 30 to 34.9, 35 to 39.9 and greater than 40 are associated with progressive levels of obesity. For each increased level of obesity, you are at a greater risk of cardiovascular disease and diabetes, warns the Centers for Disease Control and Prevention.

Considerations

While the correlation between BMI and body fat is high, the BMI has been criticized as not providing a truly accurate representation of body fat or disease risk, reports the Centers for Disease Control and Prevention. For example, women tend to have a higher percentage of body fat than men, older people have more body fat than younger people and those with more musculature will have higher BMIs that aren't necessarily associated with adverse health effects. Therefore, the BMI is most accurate when compared to other assessments such as waist circumference and blood pressure readings. Children are measured on a different BMI chart than adults.

Recommendations

If you have a BMI of 30 or more, you should lose weight. A 5 to 10 percent reduction in weight can reduce the risk of obesity-related diseases, advises the National Heart Blood and Lung Institute. Other risk factors that may warrant a weight-loss program include high blood pressure, high blood-fat content, physical inactivity, smoking and a family history of heart disease. Consult your physician before attempting to lose weight.