BMI calculator

What is BMI (Body Mass Index)?

The society that was birthed by the modern human race places vast quantities of importance on the way you appear physically. Chief among the standards for an attractive appearance is one’s body weight. If your body possesses quantities of fat that can be be labeled excessive, there will be difficulties in existence for other people to consider you to be attractive. A low fat count is so integral to one’s physical attractiveness that people will resort to doing virtually anything that is in possession of the possibility of being capable of assisting you to shed the undesirable amounts of pounds from their bodies forever and obtain a more attractive appearance. Some individuals attempt to battle fat by devoting hours to physical, rigorous exercise in order to transform their body and make it as attractive as possible. Other people decide to adapt to new diets, ridding themselves of tasty but unhealthy foods in order to end the accumulation of undesirable fat and slim themselves down. Some people even attempt to eliminate fat by consuming weight loss supplements, that are usually formed as questionable diet pills or meal replacement shakes designed to enhance the metabolic functions of your physical body and reduce their daily intake of calories.

The amount of pounds weighed by your body is about more than just physical attractiveness, though. While high fat content certainly makes people less attractive in the considerations possessed by their peers, this can additionally frequently result in a serious of health affliction, ranging from everything to Diabetes to cardiovascular heart problems. In fact, while a sizable quantity of diet plans overweight individuals turn to focus on destroying weight with intended result of becoming more physically attractive, the majority of them are actually of the design to correct your unhealthy eating patterns and educate you on the proper foods to select when decisions are made in the relation to how to feed yourself, to make the possibility to maintain beneficial state of health that will provide the allowability to avoid experiencing health afflictions as your ages grows and increases. The less excess fat exists on your body, the healthier you will be less in possession of the likelihood to experience high quantities of diseases and afflictions.

Clearly body weight plays a critically vital role in every individual’s lives. Whether your fat destruction is motivated by the desires you possess to be more attractive or healthier, or even if you’re simply conscious of maintaining your current amount of pounds in a healthy position, you no doubt devote many of your thoughts towards your body weight. However, do we know how to talk about body weight in an informed way? What science and research is behind the concepts of “overweight” and “morbidly obese”, and how can it be possible to the ascertain  knowledge of if the current amount of fat contained by your body is healthy or unhealthy? Fortunately, this article contains the information necessary to obtain to answer those questions. Throughout this article you will learn the system for determining healthy and contrasting unhealthy weight values: the Body Mass Index.

The Body Mass Index is a system that involves determining the ratio that represents your height against your weight, so that the determination can be made of if the amount of weight contained in your body is a healthy amount to be possessed by an individual of your height. As an ensuing result of its small margin for error, the Body Mass Index is quite often employed as a method to determine weight-related trends that emerge in sedentary populations. However, the Body Mass Index is also employable on an individual level to calculate the healthy amount of weight you should be depending on by how tall you are. Due to the system’s popularity and effectiveness, the World Health Organization has considered the Body Mass Index to claim the title of the standard for determining and recording statistics related to obesity since the early years of the1980s.

If you possess the desire to continue acquiring more knowledge pertaining to the Body Mass Index, continue reading this informational review of the system of measurements to obtain all of the knowledge necessary to understand how the Body Mass Index works, how to make calculations to uncover your own BMI, and how healthy or unhealthy the amount of fat content in your possession is viewed as being.

Who Invented BMI?

The Body Mass Index was initially developed within the range of the years 1830 and 1850 by he who’s hailed as the father of “social physics” himself, Belgian astronomer, statistician and sociologist Adolphe Quetelet. As you can ascertain from the variety of titles that can be claimed by Quetelet, he was a man in possession of many professions and talents. It was actually Quetelet who proposed and proved that modern populations of people are actually in possession of enough variation for both artificial and natural selection to continue to operate within them. While his contributions to medical science are not extensive, the Body Mass Index has changed very little from the system that Quetelet proposed in the nineteenth century, which means that his concepts and designs have survived over 100 years and still continue contributing to our understanding of health and body weight to this very day.

Popularization of the Body Mass Index

While Adolphe Quetelet has been historicized as the original creator of the Body Mass Index, the modern definition and implementation of the system were primarily introduced to the public by a scholarly article penned by American Scientist Ancel Keys. Keys was a popular epidemiologist who made significant contributions to the study of cardiovascular conditions, in addition to the creator of the Mediterranean Diet, which continues to be a highly popular method for weight loss to this very day.

Keys’ article on the Index originally saw publication in an issue of the Chronic Disease Journal in 1972. Within the article, Keys presents the Index as an employable method for measuring and classifying the average body composition of a population that is sedentary, or physically inactive. In fact, Ancel Keys specifically states in his article that the Body Mass Index is really much more appropriate for calculating the weight of populations, rather than individuals. However, due to public interest it has become incredibly common for the system to be employed so single people can determine where their body weight falls on the Index.1

Adolphe Quetelet (left) and Ancel Keys (right) – the men responsible for creating and popularizing the Body Mass Index, respectively.

In the contemporary day, use of the Body Mass Index has only increased in popularity as an epic of obesity continues to sweep across the western societies that scrutinize body weight more so than other cultures in existence. Body Mass is also commonly used today to perform calculations on the weight possessed by adults and younger children too to allow to possibly predict future health complications that may strike as consequences of their body weight.

How Does BMI Work?

Now the knowledge is yours that the Body Mass Index is what can be explained as a system for determining whether your possessed weight quantity is considered healthy or unhealthy. But how does the Index work? How are the health values of your weight determined?

Before you are instructed on how to complete calculations to make the determination of your own BMI numerical value, there is a crucial understanding that must be obtained as how the system functions. Depending on the value that your BMI is calculated as existing as, you can fall anywhere between underweight and obese. Obviously it is unhealthy to be either of those things, so your desire should be in possession of an amount of weight that lands you towards a healthy spot located relatively in the middle between those two categories.

The Ranking System of the Body Mass Index

Fortunately the way the Index is arranged is extremely easily followed by all. The higher the number, the less healthy the ratio existing between your measured height and between your weight is classified as being. As your BMI increases, as does the likelihood that you’ll have vulnerability to various health afflictions. The Index is divided into several different categories, comprised of the numbers that represent “underweight”, “healthy weight”, “overweight”, “obese” and “extremely obese”.

The Index considers the following BMI measurements to be defined in the following categorizations:2

How to Calculate BMI

When proceed with calculations of your BMI there are primarily two genetic factors to be considered. These two important genetic factors are your height, and of course your weight. Your height and additionally your weight will be the two values that are actually used to complete the determination of where you are categorized on the Index. These values are typically measured in meters and kilograms.; however, inches and pounds is capably employable if you make the necessary conversions into the metric system.

Now that the historical information of the Index has been learned, in addition to why it’s employed and what genetic factors are utilized as you determine your place on the spectrum as well, it is finally time to receive the knowledge of making the calculations that will reveal your personal BMI and where you rank on the Index.

The Body Mass Index Equation

For the calculation of your BMI, the number which will be responsible for your placement on the Index and thus how healthy your current weight is scientifically and medically considered to be, you’re going to have to do a little math. Once you have the numbers that represent your height measurements and your weight, you are going plug them into the formula that is used to calculate the BMI of a person. To accomplish this calculation, you will be dividing your mass (the amount of kilograms or pounds that you weigh) by your height squared. There is one additional component of the formula if you are determining your BMI by using pounds instead of grams  and inches for meters: you must additionally multiply the sum of the completed equation by 703. Thus, the equation to be employed to determine your BMI looks like this:3

By utilizing the formula of this equation the possibilities will exist for you to make the calculation of the BMI for any individual, providing you are in possession of the knowledge of their height and weight. For instance, let’s determine the body weight of an individual subject who is 65 inches tall (5’10) and weighs 160 pounds. To do this, we will plug those numbers into the formula that we have just learned:

pounds ÷ (inches x inches) = X x 703 = BMI

160 ÷ (65 x 65) = .038 x 703 = 23

So our 5’10, 160 pound subject is in possession of a BMI of 23. Using this number, we can then determine whether 160 pounds is a healthy amount of weight for a 5’10 individual to be. Now that we have determined this number, we can refer to the way that the Body Mass Index arranges itself in order to see whether or not 23 is a healthy Body Mass Index for a person to have.

According to the standards of the Index, our 5’10, 160 lb subject of the calculation we performed earlier, who ended up having a BMI of 23, falls just into the category of being of a healthy weight. However, they are very nearly approaching a weight that the Index would consider to be unhealthy. If our subject’s BMI was a mere two numbers higher, the individual would be considered to be overweight by medical and scientific standards, according to the Index.

Prime BMI

There is also another number that you can calculate in order to determine the value of your BMI Prime, which simply put is the ratio of your body weight to the limit of your upper body-weight, which is the lowest number you can possibly have while still being classified as being a healthy weight. When the fact is considered that the BMI that begins to constitute the status of “overweight” is 25, you can tell if you are overweight or not depending on whether or not your BMI value exceeds 25. In order to discover your BMI Prime, you will simply need to divide your BMI by 25. Since a BMI of 25 divided by 25 equals 1, BMI Primes that exceed 1 are considered to represent unhealthy excess weight, whereas BMI Primes that fall relative close to but below that number constitute healthier weights for you to be.

Let’s try this using our subject who had a BMI of 23. 5625

23 ÷ 25 = .92 Prime BMI

Since we have calculated that our subject’s Prime BMI is .92, we can determine the percentage of how close the individual is to the upper body weight limit. Individuals who meet the upper body weight limit exactly should have a BMI of 25 and a BMI Prime of 1. The percentage of how close you come to this limit is defined by the number following the decimal point in your BMI and how far away it is from 1. For example, our subject’s prime BMI is .08 less than 1. This means that our subject is 8% less than the upper body weight limit as defined by the Body Mass Index. On the other hand, if an individual’s BMI is, say, 34, they will have a Prime BMI of 1.36%, which means that they would be exceeding the upper body weight limit by 36%. There is probably no need to make an explanation, but the greater your Prime BMI exceeds 1, the unhealthier the amount of body weight in your possession is viewed as.

Why is BMI So Important?

The thing that can be said to make the Body Mass Index a valuable and integral element in the way the medical as well as the scientific community approach an understanding of body weight as related to physical aspects of health, is for the possibility for which it allows us to study health trends and assess potential health risks. For example, on an individual scale, determining one’s BMI can frequently prove effective in helping to predict and protect from health afflictions or diseases that one may be likely to face in future years.

If the BMI in your possession is one that is high, the possibility will be in existence for you to obtain an understanding of the possible afflictions the experience of which you may be risking as you become more vulnerable with the increase of your age. For example, people whose categorization meets that of overweight or obese by the Index are typically of an increasingly greater risk of experiencing cardiovascular complications and issues like heart disease and heart attacks. A high BMI is also an indication that you are risking a more likely development of type 2 diabetes, an incurable disease which can afflict you for your remaining life. Individuals with high BMIs are even known to placed to risk greater kind for getting certain cancer types. Fortunately, your doctor will predict these risks once determining your BMI and take the appropriate measures to assess them.

Using your BMI to arrive at the determination of if you possess the classification of underweight is of course of equal value to the employment of using the number to ascertain whether you of the classification of overweight or obese. If after calculating your BMI you arrive at the conclusion that your classification is that of underweight, there is the possibility for this to mean that you are undernourished as well. This may motivate you to alter your dietary patterns in order to include the provision of the proper nutrition that is of the necessity for your physical body to function properly. However, learning that you are undernourished may also potentially lead to the revelation that you may be suffering from some kind of disorder that prevents your body from properly absorbing the types of nutrients that are required for it to operate, so you will be able to seek treatment and hopefully a solution to what could be a critical health issue.

There are numerous quantities of examples to be found that illustrate what a valuable role that the Body Mass Index can potentially play in studying health-related trends within populations (which is the intention for the system that Ancel Keys initially had in mind when he chose to introduce the Index to the general public). One such study, performed by the Journal of the American Medical Association in the year 2005, actually employed the Index in studying death rates among populations of different weights. By using the Body Mass Index, the American Medical Associated determined that individuals that the Index had determined were of a normal weight, or even those that could be under the categorization of overweight, had a smaller death rate than those falling under the categorization labeled either obese or underweight.

Things to Keep in Mind When Utilizing the Body Mass Index

While the Index has long existed as a method that is considered to be effect when the determination of what weight is classified as having the amount needed to be medically healthy and fit, it is not universally a perfect system to go by when measuring one’s physical health in accordance with how much fat exists on your body.

For example, one aspect of study where the BMI falls short is in its failure to differentiate the difference between fat mass and between muscle mass. Knowledge that may already be in your possession is that the weight of muscle is actually greater than the muscle of fat. Always present is the e chance that two individuals may weight exactly the same amount, even though one’s weight comes from unhealthy fat while the contrasting individual’s comes from healthy muscle. If these muscular and fat individuals who weigh the same amount also happen to be of identical height values, they will have identical BMIs. Unfortunately, this is but a single occurrence illustrating how BMI might fall short in determine how healthy an individual’s amount of body weight is.

Another way in which the Index can occasionally fall short is in its faulty recognition of physical characteristics. The Body Mass Index actually adds 10% for what it considers to be tall or large subjects and subtracts the same amount for subjects of a shorter or smaller height. What happens as a consequence of this is that subjects with smaller frames who are in possession of more increased quantities of body fat than they should have are frequently misled into believing that they possess a normally healthy BMI. According to Nicholas Trefethan, the head of Numerical Analysis at Oxford University’s Mathematical Institute, the number by which the Index divides the weight of short people is much too small, whereas the one it uses to divide the weight of individuals with larger frames is too big. The viewable consequences of the discrepancy is that individuals with smaller frames are frequently convinced to possess the belief that the weight in their possession is of a healthier value than should actually be believed by them, whereas taller individuals are in possession of a greater likelihood to be considered fatter than the standards of the Index actually describe.

While the Index has proven to exist as an invaluable method for making the determination of what amounts of weight can be considered to be of a  healthy or unhealthy value, common sense and logical health assessments must also be in a present role when considering one’s physical health in what ties may exist to their weight. The Body Mass Index system may not prove to be ideal in assessing the relation of your body weight content to your physical health. If you do not accomplish success by employing the Body Mass Index, you should investigate other methods to use in assistance when coming to a more increased understanding of your physical health and how the presence of fat, or lack thereof, can impact it. However, while these alternatives may be valuable for learning more about your body weight and the state of your physical health, the Body Mass Index certainly has the appearance of an effective assessment method that will persist being employed by the medical and scientific community for the future that is able to be foreseen and can be of great personal use to you as well.

BMI Table for Adults

As has been discussed in previous sections, the Body Mass Index‘s shape can be arranged in table form that illustrates the spectrum that spans from severely underweight on towards obesity of the third class. For your convenience, such a table can be referenced below:4

As can clearly be viewed by this convenient table, as your BMI falls farther outside the range of 18.5 to 25, you become classified as an unhealthier weight than you should be. While overweight individuals are of relatively less risk of experiencing health afflictions than those with even higher BMIs, if you are severely underweight or obese in any way you should consider contacting your preferred medical specialist and increase your knowledge of how you can maneuvers can be planned for the allowance of you to achieve a value representing a healthier weight that will reduce the quantities of risks involving facing the experience of any kind of physical ailment that relates to you body’s weight’s value, such as diabetes and even additionally heart disease.

BMI Chart for Adults

Many sources are in existence that are available for you to complete the determination of where you can be categorized under the Body Mass Index within accordance of your personal BMI. When performing consideration of the concept that the Index is really more of a spectrum in opposition to a more essentially simplified system of ranking your body weight, it can frequently be easier to determine your specific BMI by consulting one of the readily available Body Mass Index charts that are locatable online for free. However, for your convenience, a chart designed to establish the determination of your BMI has been included below:5

BMI Table for Children and Teens

While the methods employed for calculating and establishing the determination the BMI of a fully-grown adult are fairly straightforward, arriving at the determination of the BMI of a younger, developing child or adolescent teen whose body is still developing requires a little extra consideration. While the calculations are performed the same way, the number representative of a younger child or adolescent teen’s BMI must also be compared to values of other young children or adolescent teens who are possession of a similar age value as the subject. Instead of using fixed numbers to reach the determination of whether a younger child or adolescent teen whose body is still developing, you will be comparing the BMI of the subject to where other subjects in possession of similar age values fall on the Index’s spectrum. When determining the health value of a younger child or adolescent teen’s BMI, you will be looking at the percentage of their peers who fall above and below them. A subject is categorized of existing with a healthy weight if they range anywhere between the 5th and 85th percentile of their peers. Young children and adolescent teens who fall below the 5th percentile are categorized in they way of belonging to the classification of underweight, whereas ones who register between the 85th and 95th percentile are of the category to be described as overweight. A younger child or adolescent teen’s body weight must rank within the top 5 percent of their peers in order for the subject to be considered obese.

In accordance with convenience, an easy to consult table created with this information is below:6

BMI Chart for Children and Teens

While we’ve established that it is entirely possible to calculate and determine the BMI of a younger, developing child or adolescent teen whose body is still in some stage of development, this can frequently be a difficult task when the fact is made to be considered that you must then compare that number to the BMI values of the subject’s peers. To make this easier for you, two charts tracking the common BMI values of young children and adolescent teens, both boys and additionally girls, have been included here for your reference.7

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