what is body mass index

Hello, Fitness Freaks. What is Body Mass Index? OR What is BMI? BMI (Body Mass Index) is a measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters. BMI is used as a screening tool to indicate whether a person is underweight, overweight, obese or a healthy weight for their height.

In this Article, we will study deeply about what is Body Mass Index (BMI) deeply.

What is body mass index

Also, Read.:-

  1. What is Obesity?
  2. Top 20 Health Remedies for weight loss

What is Body Mass Index?

1.    BMI Definition
2.    Calculation Of Body Mass Index
Ø Formula of Body Mass Index
Ø Body Mass Index Charts

3.      BMI Table for Children and Teens (Age 2-20)

4.    Conclusion


BMI Definition

  • Body Mass Index (BMI) is a measurement of a person’s weight with respect to his or her height. It is more of an indicator than a direct measurement of a person’s total body fat.
  • Body mass index (BMI) is a measure of body fat based on your weight in relation to your height and applies to most adult men and women (aged 20 and over).
  • Body Mass Index (BMI) is a measurement of a person’s weight with respect to his or her height. It is more of an indicator than a direct measurement of a person’s total body fat.
  • BMI values are age-independent and the same for both sexes. However, BMI may not correspond to the same degree of fatness in different populations due to different body proportions.
  • BMI, more often than not, correlates with total body fat. This means that as the BMI score increases so does a person’s total body fat.
  • —abbreviation BMI— called also Quetelet index


Health Risk Related to a High BMI

The reason the BMI is used for screening the health of the general population is due to the strong correlation between being overweight or obese and having health problems, chronic disease, and premature death. People who are overweight or obese have an increased risk for the following health conditions:

  • Hypertension
  • Type 2 diabetes
  • Coronary heart disease
  • Stroke
  • Osteoarthritis
  • Some Cancers
  • Sleep apnea and respiratory problems


Calculations of Body Mass Index

Body Mass Index Formula

1. Metric BMI Formula

BMI = Weight (kg) / Height (m)2

With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared (kg/m2). Since height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height in meters.

2. Imperial BMI Formula

BMI = (Weight (lbs.) * 703) / Height (inches)2


When using pounds and inches, the formula needs to be altered slightly. Multiply your weight in pounds by 703. Divide that by your height in inches, squared.

Body Mass Index (BMI) Weight Status
Below 18.5 Underweight
18.5 – 24.9 Normal
25.0 – 29.9 Overweight
30.0 plus Obese


  • A body mass index in adults of below 18.5 then it is considered an indication of Underweight, and 18.5 to 24.9 then it is said to be Normal BMI.
  • A body mass index in adults of 25 to 29.9 is considered an indication of overweight, and 30 or more an indication of obesity.
  • If a person’s BMI is out of the healthy BMI range, their health risks may increase significantly.

Calculate Your Body Mass Index (BMI):- Click Here.

Body Mass Index Charts 

The WHO international classification of adult underweight, overweight, and obesity according to BMI

Classifications BMI (kg/m2)
principal cut-off points
Underweight <18.50
Severe thinness <16.00
Moderate thinness 16.00-16.99
Mild thinness 17.00-18.49
Normal range 18.50-24.99
Overweight ≥25.00
Pre-obese 25.00-29.99
Obese ≥30.00
Obese class, I 30.00-34.99
Obese class II 35.00-39.99
Obese class III ≥40.00

BMI Table for Children and Teens (Age 2-20)

BMI is Used Differently with Children than it is with Adults In kids and teenagers, body mass index is utilized to survey underweight, overweight, and hazard for overweight. Youngsters’ body heftiness changes throughout the years as they develop. Additionally, young ladies and young men contrast in their body heftiness as they develop. This is the reason BMI for kids, likewise alluded to as BMI-for-age (BMI for Children and Teens is now and again alluded to as “BMI-for-age”), are gender and age in particular. BMI-for-age is plotted on gender-particular development graphs. These outlines are utilized for kids and adolescents 2 – 20 years old. For the 2000 CDC Growth Charts and Additional Information visit CDC’s National Center for Health Statistics.

Every one of the CDC BMI-for-age gender particular graphs contains a progression of bent lines demonstrating particular percentiles. Social insurance experts utilize the accompanying built up percentile cutoff focuses to distinguish underweight and overweight in youngsters.

Underweight BMI for age < 5th percentile
At Risk of Overweight BMI for age 85th percentile to < 95th percentile
Overweight BMI for age > 95th percentile

BMI diminishes amid the preschool years, at that point increments into adulthood. The percentile bends demonstrate this example of development.

What does it mean if my youngster is in the 60th percentile? The 60th percentile implies that contrasted with offspring of a similar gender and age, 60% have a lower BMI.

Case: Let’s take a gander at the BMI for a kid as he develops. While his BMI transforms, he stays at the 95th percentile BMI-for-age.

Age BMI Percentile
2 years 19.3 95th
4 years 17.8 95th
9 years 21.0 95th
13 years 25.1 95th

We perceive how the kid’s BMI decreases amid his preschool years and increments as he gets more established.

Why is BMI-for-age a valuable instrument? BMI-for-Age is utilized for youngsters and adolescents due to their rate of development and improvement. It is a helpful apparatus on the grounds that:

  • BMI-for-age gives a reference to youths that can be utilized past adolescence.
  • BMI-for-age in kids and youths thinks about well to research center measures of body fat.
  • BMI-for-age can be utilized to track body estimate all through life.


In this article, we have study detailed about Body Mass Index (BMI). 

The points covered in Articles are:-

BMI Definition: – Body Mass Index (BMI) is a measurement of a person’s weight with respect to his or her height. It is more of an indicator than a direct measurement of a person’s total body fat.

Calculation of BMI:-

  • Metric Formula:-

BMI = Weight (kg) / Height (m)2

  • Imperial formula:-

    BMI = (Weight (lbs.) * 703) / Height (inches)2

Body Mass Index Charts:-  Different charts for classification of BMI on The bases of age and other factors

BMI Table for Children and Teens (Age 2-20):- Children over age 2, or teens whose BMI is: Less than the 5th percentile is considered underweight. Between the 5th percentile and less than the 85th percentile are at a healthy weight. In the 85th percentile to less than the 95th percentile are considered overweight.

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