Body composition measurements


Body mass index: Body mass index (BMI) is a tool for indicating weight status in adults. It is a measure of weight for height. For adults over 20 years old, BMI falls into one of these categories: Below 18.5 (underweight), 18.5-24.9 (normal), 25.0-29.9 (Overweight) and 30.0 and above (obese). BMI correlates with body fat; BMI does not measure body fat. The relation between fatness and BMI differs with age and gender.
Waist to hip ratio: Waist to hip ratio (WHR) is the circumference of the waist (smallest part of the torso, usually slightly above the navel) divided by the circumference of the hips (largest part of the buttocks). This ratio may indicate body fat distribution and obesity and potentially the risk for certain diseases, such as diabetes, high cholesterol and cardiovascular disease.

Related Terms

Adiposity, apple-shape, body surface area, BMI, BMI calculator, cardiovascular disease, diabetes, fat distribution, head circumference-for-age, high cholesterol, hips, lean body mass, metabolic syndrome, obese, obesity, overweight, pear-shape, stature-for-age, underweight, waist, waist circumference, weight-for-age and weight-for-length percentiles, WHR.

charts and calculators

Body mass index (adults): English: 703 x [Weight in pounds/(Height in inches) x (Height in inches)]. Metric: [Weight in kilograms/(Height in meters) x (Height in meters)].
Body mass index (children): The formula for adult BMI can be used with children, although the results are interpreted differently. BMI charts showing percentiles are used with children 2-20 years of age. Related growth charts include head circumference-for-age (infants 0-36 months), weight-for-length percentiles (infants 0-36 months), stature-for-age (2-20 years) and weight-for-age (2-20 years).
Hip to waist ratio: Divide waist circumference (measure around the smallest part of the torso, generally slightly above the navel) by hips circumference (measure around the largest part of the buttocks) to determine the hip to waist ratio. For women, a healthy ratio is 0.8 or lower, and for men it is 1.0 or lower. Note: The lowest healthy ratio is not known. Although the waist to hip ratio may indicate where fat is distributed on the body, it does not predict the risk of any disease. According to the American Heart Association, WHR is less accurate than body mass index (BMI) or waist circumference and is no longer recommended.