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BMI and WHR calculators: health status indicators
BMI and WHR calculators: health status indicators

BMI - Body Mass Index: what it is and how to calculate it

The body mass index, known as BMI, from the English Body Mass Index , is a parameter that serves to establish whether your body weight is within normal limits, or how far it differs from what is defined as the "Ideal weight".

In order to evaluate this parameter we need two values: the weight, expressed in kg, and the height, expressed in meters. The calculation is very simple, and allows us to obtain a statistical value to analyze the body and nutritional status of a subject. It is certainly one of the best known and most used anthropometric measures, but it must be remembered that it has a statistical value, with a rather high margin of error. It should always be contextualized on the basis of the subject and integrated with other body composition measurement techniques (such as, for example, skin test) because it does not distinguish between fat mass and lean mass.

How is it calculated

The formula is as follows:

body weight (kg) / height X height (m)

after having obtained a numerical value, it will be sufficient to compare it with the appropriate reference tables to evaluate in what body conditions we are.

In general, the subdivision occurs as per the following table:


Weight condition


Severe underweight


Moderate underweight


Mild underweight






Mild or 1st degree obesity


Moderate or 2nd degree obesity


Severe or 3rd degree obesity

Per example, if you are 1.70 m tall and weigh 70 kg, your BMI is 70 / 1.65 2 = 24.2 : perfectly in the normal weight range.

Below we leave a BMI calculator, to be used to get a first impression on our body mass condition:


But are we sure that the BMI is sufficient?

To accurately assess the health and nutritional status, it is also necessary to know the percentage of fat mass and lean mass. Above all, these two parameters are those able to make us better understand our weight condition. As is now well known to most of the population, muscle "weighs more" than fat mass, despite the fact that the volume occupied by muscle mass is actually less. This leads individuals with high muscle mass to fall into the category of overweight for the calculation of BMI, despite having an ideal body composition and being in full health.

So ... Is the BMI reliable?

Yes and no! As with any parameter, you must always be able to relate the results obtained to the specific situation. In the case of BMI, we can use this indicator to get an idea of ​​our state of health, but keeping in mind that with this simple calculation it is not possible to really know our body composition, and therefore understand if it is normal or if the overweight is due to an excess of fatty tissue.

Homemade measurements that can complement BMI

The WHR is undoubtedly one of the anthropometric measures that are easy to reproduce even in one's own home and which allow for the integration of the BMI calculation. It will take a tape measure and a few minutes. But let's go in order: let's understand what this parameter is and what it is for, and why it is useful to integrate it to the calculation of BMI.

Calculation of the waist-to-hip ratio or WHR (waist to hip ratio)

The WHR expresses the relationship between the circumference of the waist and that of the hips, and is used in the medical field to evaluate the body distribution of adipose tissue. It partially compensates for the deficiencies of the BMI, because it allows to have an idea of ​​the distribution of body fat, which is related to cardio-vascular diseases. Several studies have shown that android obesity (ie the "apple-like" physique typical of humans) is related to higher levels of blood sugar, blood pressure and triglycerides, while gynoid obesity (ie "pear-shaped", typical of women) is less dangerous to health.

How is it calculated

The formula is as follows, and you just need to enter the measurement in cm of the waist and hip circumference to get your WHR value.


Understanding the waist-to-hip ratio

According to the European guidelines, the waist / hip ratio should be:

  • In Man less than 0.9
  • In women less than 0.8

A WHR higher than 0.95 for men and 0.85 for women indicates an increased risk for the development of various diseases, and therefore for individual health. The waist-to-hip ratio is a proven indicator of future cardiovascular disease, diabetes, hypertension and gallbladder disease (source ).


These 2 values ​​are not the only ones useful for determining the " healthy weight " or " optimal physical fitness ": the correct thing to do is always to evaluate several health indicators as a whole, to contextualise the parameters in the best possible way.

The BMI measures the total body mass: remember that people with "out of the ordinary" builds (very tall, very short, bodybuilders or competitive athletes) risk obtaining false results. The WHR, on the other hand, is more truthful from this point of view, because it represents a relationship of “natural” proportions, for both men and women.


We are waiting for you in the comments to find out which other calculators can do for you!



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