“BMI or Body Mass index is nothing more than a number. To what use you put that number to is what makes it important. It’s your unique number”.

BMI is ultimately an index coined to assess the body composition and weight risk – if you are underweight or obese. Started as a tool to assess weight issues of a population section rather than for individual use, today this has evolved into a daily-use household tool.

Lets read on in detail about this weight risk calculator and how BMI Calculator got about to be the most widely used weight risk index across the globe..!

## BMI – the Number:

The Body Mass Index (BMI) is a value derived from the mass (weight) and height of an individual. It is defined as the body mass divided by the square of the body height in units of kg/m2. BMI is ultimately an attempt to quantify the amount of tissue mass (muscle, fat, and bone) in an individual, and then categorize that person as underweight, normal weight, overweight, or obese based on that value.

The BMI may also be determined using a table or chart which displays BMI as a function of mass and height using contour lines or colours for different BMI categories – BMI Chart. (See Image)

However, there is some debate about where on the BMI scale the dividing lines between categories should be placed.

### How is the number a measure of weight composition?

Thus for an individual, with his current height, which can usually be considered constant for short periods, his weight can be checked for abnormalities by calculating up their BMI no. and seeing if it falls in the prescribed normal region of BMI which is by commonly accepted standards world-wide (WHO as well) should fall between 18.5 and 25.

The demand and interest in an index that measures body fat grew exponentially with increasing obesity in prosperous Western societies, which was a great factor which contributed to the pan-global acceptance and usage of BMI as a satisfactory weight-risk analyzer.

But a limitation of BMI is that it does not differentiate between muscle mass and fat mass. Thus an athlete who is essentially fit with a large muscle mass but no body fat also tends to have an abnormal BMI which is not the case. Similarly, as the height element is being squared for calculation, there is a tendancy for tall people to get larger BMI result even if they don't have excess body fat.

Originally BMI was designed for weight risks in population studies (a large section of people) and not on individuals. It was later, on wide usage, that they started being used for individuals as well.

Even with these limitations, Body Mass Index is still a widely used weight risk indicator globally accepted. Why?

### How exactly can BMI be utilized by an individual?

Body weight risk is something that needs constant monitoring and is important that an optimal weight is maintained throughout the life.

In this regard, Body Mass Index provides a simple numeric measure of a person's thickness or thinness, allowing oneself to make regular, simple and basic assessment of their current body composition. It also gives health professionals an objective way to discuss weight problems with their patients.

BMI is a reasonable indicator of body fat for both adults and children.

But as BMI does not measure body fat directly, it should not be used as a diagnostic tool. But for a preliminary diagnosis, BMI is always a sufficient index.

Depending on a valid BMI calculator to regularly check your weight status and for preliminary diagnosis is thus a healthy habit.

But never use the index to declare an individual unhealthy or unfit.

## BMI in children (aged 2 to 20)

BMI is used differently for children. It is calculated in the same way as for adults, but is compared to typical values for other children of the same age instead of comparison against fixed thresholds. The BMI is compared against the percentile for children of the same sex and age.

A BMI that is less than the 5th percentile is considered underweight and above the 95th percentile is considered obese. Children with a BMI between the 85th and 95th percentile are considered to be overweight.