# Body mass index calculator

Body mass index (BMI) is the ratio of a person's height to weight. The online BMI calculator will quickly answer the question of concern to many about the presence or absence of excess weight.

## History of BMI

The Belgian Lambert-Adolph-Jacques Quetelet was the first to propose to calculate the body mass index using the formula "weight in kilograms divided by height in centimeters squared" in 1835. The Belgian scientist was a mathematician, meteorologist, astronomer and sociologist, but the founder of scientific statistics became famous for the invention of the concept of "body mass index". The Quetelet formula became widely known 140 years later, after the research of the physiologist Ancel Keys, who analyzed the data of 7.5 thousand people from different countries.

The BMI value is only applicable for indicative estimation, since there are many nuances that are not taken into account in the formula. For example, with its help it is impossible to objectively assess the physique of athletes, since developed muscles are heavier than fat.

Later, the shortcomings of the method were partially compensated in other systems that take into account the volume of the body:

**Brock's index.**Relatively accurately reflects the picture with a height of 155–170 cm. According to Broca, normal body weight = (height in centimeters - 100) ± 10%.**Breitman index.**Normal body weight = height in centimeters × 0.7 - 50 kg.**Bernhard index.**Ideal body weight = height in centimeters × chest circumference in centimeters / 240.**Davenport Index.**A person's weight in grams is divided by their height in centimeters and squared. If the indicator exceeds 3.0, we can talk about obesity.**Noorden index.**Normal body weight = height in centimeters x 0.42.**Tatonya index.**Normal body weight = height in centimeters minus (100 + (height (cm) × 100) / 20).

Also, in addition to height and weight, the thickness of the skin fold at the level of the third rib is measured. Normally, it should not exceed 1.5 centimeters.

## Disadvantages of the method

It turns out that the amount of body fat in the body is not always expressed in increased BMI. For example, in Finland, 20% of men and 30% of women are overweight, with the vast majority having a normal body mass index. The reason for the discrepancy is in a sedentary lifestyle and minimal muscle volume.

In addition, BMI does not take into account gender and age, although statistics confirm that men and middle-aged people have a higher BMI than women, young and old people.

The BMI norm has changed several times over the past decades. So, until 1998 in the USA, the normal BMI was 27.8 kg/m², after that the index was set at 25 kg/m². As a result, almost 30% of Americans fell into the category of obese.

It is worth listening to the opinion of experts who believe that the most objective reflection of a person's state of health is the shape of the body and the figure of a person. In any case, body size can accurately diagnose the risk of diseases of the cardiovascular system and type 2 diabetes.

You can maintain health by focusing on any system - an active and healthy lifestyle is expressed in kilograms, centimeters and well-being. Calculate your body mass index with a calculator and stay optimistic.