Body mass index

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What is the body mass index?

The body mass index ( IMC or BMI, English acronym of Body Mass Index) is a parameter that relates the body mass and the height of a subject. The IMC provides a more accurate estimate of body size than the old tables based simply on height and weight.

The body mass index is calculated by dividing your weight expressed in kg by the square of the height expressed in meters:

BMI = body mass (Kg) / height (m2)

According to this formula, the body mass index of a person who weighs 75 kilograms and is 1 meter and 80 centimeters high will therefore be equal to:

75 / (1.80 * 1.80) = 75 / 3.24 = 23.1

According to the World Health Organization, the BMI, or body mass index, can be grouped into 4 categories:

underweight (BMI below 19)
average (BMI between 19 and 24)
overweight (BMI between 25 and 30)
obesity (BMI above 30)

Desirable BMI

The table below provides information about the desirable body mass index in relation to the age of the individual.

Recall that the body mass index is not a usable parameter for individuals under the age of 18. In these cases, in fact, it is necessary to resort to the specific growth curves that correlate the age, sex and weight of the subject.

With regard to elderly individuals, instead, the body mass index tends to decrease over the age of 70-75, due to the loss of body weight that usually occurs starting from this age.

Finally, it should be pointed out that the BMI is not a parameter that can be used during pregnancy. Therefore, its calculation during gestation is not considered useful.

Age in years	Desirable BMI
19 - 24	19 - 24
25 - 34	20 - 25
35 - 44	21 - 26
45 - 54	22 - 27
55 - 64	23 - 28
> 65	24 - 29

Online calculation

To calculate your body mass index, enter your body weight, expressed in kilograms, and your height, expressed in centimeters, in the boxes below. Then, click on the "Calculate body mass index" button.

The body mass index is a very important parameter. In addition to being used for the classification of overweight and obesity in adult men and non-pregnant women, BMI is also an epidemiological index. In fact, there is a profound correlation between body mass index and mortality risk due to cardiovascular complications (including hypertension), diabetes and kidney disease.