Body Mass index (BMI) - How to calculate?

The Body Mass Index (BMI) is a commonly used calculation using the relationship between height and weight to determine how close to a healthy weight someone is. The origins of how to calculate your BMI have their distant beginnings way before obesity was a critical issue in society.

The BMI formula was developed in the early 19th Century by the Belgian statistician Adolphe Quetelet.

Though modified since its creation the measure is still used extensively, this is because it gives a range of someone, who is within a “normal” range, should weigh instead of a specific figure. It is also extensively used as it can indicate how over or underweight an individual is and can be used to suggest the rate at which they can lose weight in a healthy manner to have a sustainable weight loss.


How to calculate your BMI. The graph shows you the BMI’s indicators of underweight, healthy weight overweight and obese in relation to the various heights, the way it is calculated is outlined in the formula below:BMI = (Mass In Kg) divided by height in metres squared. 

How to calculate your BMI.

To calculate your own Body Mass Index follow the guide below or use the calculator from the graph below.

To calculate your BMI using metric units, follow this method.

 

Step 1.  Weight yourself in kilograms

 

Step 2.  Measure your height in metres.

 

Step 3.  Divide your weight by your height and then divide this number by your height again.


To calculate your BMI using Imperial units, follow this method.

Step 1.  Weight yourself in pounds

Step 2.  Measure your height in inches.

Step 3.  Divide your weight by your height and and divide this number by your height again. 

Step 4. Multiply this number by 703.

Despite it’s popularity the Body Mass Index does have some limitations because it fails to distinguish between males and females, whose body composition is different. The BMI also fails to take into consideration that muscle weighs more than fat and so many athletes and body builders are considered overweight and some are even considered obese when using this measure despite having a very healthy lifestyle.


What do the results mean?

 

According to Quetelet if you scored:

 

Less than 18.5, then you are UNDERWEIGHT.

 

Above 18.5 and below 25, then you are NORMAL

 

From 25 up to 29.9 then you are OVERWEIGHT

 

From 30 and up to 34.9 you are OBESE

 

Above this is MORBIDLY OBESE

 

 


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