# The Body Mass Index Formula

How to calculate the body mass index formula? This article shows what to do and how to interpret the Body Mass Index.

The so-called Body Mass Index, BMI for short, is a measure of body weight in relation to height. Thus, a certain person can be compared with other people in terms of weight, depending on age. Other names used to denote this index are, for example, the Quelettkaup index, the body mass index or the body mass index (or the body mass index formula).

The Body Mass Index is a formula to calculate whether your own weight is in the normal range.
The Body Mass Index formula (BMI formula):

First you take the body height times two (e.g. at 170 cm: 1.7 x 1.7 = 2.89). Then you divide your body weight (e.g. 63 kg) by the result, that is 63 : 2.89 = 21.8. This number is the body mass index. If it is between 20 and 24 you have a normal weight. If he’s under 17.5, he’s got anorexia. ## The history of BMI

This way of classifying weight was developed by the mathematician Adolphe Quetelet from Belgium. However, the quotient only received its name in 1970 from Ancel Keys, who regarded it primarily as predestined to serve as a statistical comparison within a population. The BMI was widely used by American insurers, who calculated the amount of the premium on the basis of the value. From 1980, the BMI was also recognised by the WHO, the World Health Organisation, as a standard procedure for assessing underweight, normal and overweight.

## The calculation of the BMI

The body mass index is calculated by a simple quotient. The body weight in kilograms is divided by the body height in meters squared. In the case of missing limbs, correction values were developed which are offset against the body weight, so that a fictitious body weight can be used to determine the index. Otherwise, the value for people with amputated limbs would always be lower than it should be.

For the simple calculation of the measured value, there are BMI calculators on various websites on the Internet, with the help of which this can be determined. Since these BMI calculators often already perform an evaluation, there are normal BMI calculators for adults and special BMI calculators for children. Both types of BMI calculators use different standard figures as a basis for the comparison with the rate.

## The interpretation of the BMI (Body mass index formula)

In a nutshell, it can be said for adults that values between 18.5 and 25 speak for a normal weight with which one can feel comfortable, values below indicate underweight and values above that indicate overweight. The further the value deviates from the normal range, the more serious the underweight or overweight. Obesity, obesity and obesity are assumed from age 30 and obesity from age 40.

In children, classification is more difficult, as it depends firstly on gender, secondly on age and thirdly on the respective stage of growth, which varies greatly from child to child. This can indeed significantly distort the BMI.

It can be said that the normal range is shifted downwards and only approaches the normal range of adults over time.

This is due to the fact that the ratio of body size to body surface changes greatly. In case of doubt, a BMI calculator is recommended for children. In summary, the BMI is a valuable instrument of modern health and nutrition sciences and can be checked particularly well at home.