BMI Calculation Formula: Why It’s Wrong



Please please please… Listen to why this is the worst way to track yourself and your progress track yourself and your progress.

If you’re a Gym Junkie the Body Mass Index simply fails us on all fronts. With almost two-thirds of Americans being obese now, being overweight is an epidemic. However, it’s very important to understand that you’re measuring your body correctly and not getting inaccurate readings.

Yesterday I was walking through a local store when I passed the blood pressure machine; I noticed they had attached a BMI index to the same machine. I actually laughed out loud, I asked myself  “why on earth do they have this thing and how many people have been mislead by it?”.

Body Mass Index simply put is the WORST way to measure body fat percentage on an individual.

BMI Calculation Formula

BMI or otherwise known as body mass index can be determined by a simple calculation: Body weight (in kilograms) by height (in meters squared), or kg/m2.

For Example:

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If you prefer to you use pounds and inches you can use this equation: Weight (lb) / Height (in)2 x 703

For Example: If you weigh 150 pounds and your height is 5’5 (65), your calculation would look like this: [150/ (65)2) x 703 = 24.96

Now based on this calculation above if your BMI exceeds 25 heal problems could increase. Here are the obesity classifications using BMI:

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So now we have reviewed how to calculate your BMI, but here is the main problem. BMI DOES NOT takes into account the percent of body fat or lean muscle mass, so basically for Gym Junkies it’s worthless.

Let’s look in more detail why the Body Mass Index fails us…

Who Made The BMI Index?

The body mass index was created in the 19th century by Lambert Adolphe Jacques Quetelet. The problem is Lambert was a math wizard but not much of a gym junkie. The government at the time was struggling to measure obesity of the everyday person. Lambert answered by creating the BMI, but the issue is it’s over 200 years old!

Physiologically Screwed Up

Again like stated before the Body Mass Index doesn’t account for body fat, bones or muscle mass. Bones are much denser than muscle and almost twice as dense as fat. So if you’re an individual that has been drinking their milk and you have strong bones combined with good muscle tone you will most likely have a high BMI.

The simple conclusion is even if you’re an athlete the chances of you being classified as overweight or even obese is extremely high.


Gym Junkies Got Left Out Of The Equation 

BMI was intended for the “average” individual and targeted non-active individuals with low muscle mass and high in fat. That being said it will work for the average individual, but let’s be real when we’re gym junkies “average”. It gives the incorrect answer to the large portion of fit, lean and healthy people.

The Issue With BMI

Let’s be real this formula is over 200 years old developed by a math wizard not a doctor, nurse or personal trainer. Why the United States uses it to this day actually baffles me. The US and other first world countries have medically advanced machines and technologically, why use something created 200 years old?

Very little was know about the human body 200 years ago, therefore, I don’t think it should be used period.

What’s the Solution?

So now that we have explored just why you should trust your BMI “reading” what can you do to get an accurate answer? The answer is getting your body fat tested. This way you get the most accurate reading for your body. The certain body fat test formula I will give today is called the Jackson/Pollock Formula.

How to use the Jackson/Pollock Formula

It’s relatively simple to calculate your body fat, however, it varies depending if you’re a male or female. Also, your will need to purchase a Caliper to measure certain points on your body, you can either purchase one here on amazon or simply go to a local GNC get one there.

For Males: the skinfold site are located on the chest, abdominals, and thigh. SUM3 is the sum of these sites in millimeters.

Here is the Male Formula:

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For Females: the skinfold site are located on the triceps, suprailiac and thigh. SUM3 is the sum of these three sites in millimeters

Here is the Female Formula:

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Here is the key to follow:

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As you can see getting your body fat tested is a much more accurate depiction of where your body is actually standing. It just takes a simple caliper that you can purchase and keep forever to track your results. There are other ways to test your body fat, some stores have the electronic body fat tester you can find that here. The actual accuracy varies about 1-2% on the electronic version. The most accurate way to test your body fat is actually an underwater. However for convenience sake I would stick with the plastic caliper or the electronic version.

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Gym Junkies should turn to other formulas when it comes to seeking their results; BMI Calculation Formula fails us. Remember body mass index was created over 200 years ago, last time I checked I think we thought the earth was flat about 200 years ago. If we thought the earth was flat, I don’t see how we could have known too much about ourselves. That’s why I strongly recommend to test your body fat and ignore BMI it’s just inaccurate for us.

-Terry Asher

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Gym Junkies Founder & Editor in Chief at Gym Junkies LLC
I’m Terry and I’m here to help you achieve your fitness goals. I truly believe anyone can achieve the figure they want with the proper guidance. Through my extensive fitness blog, top fitness videos, leading workout supplements, and top selling eBooks, I have been able to help thousands of people online lose weight, tone up and get in shape. My passion is helping people all around the world change their lives for the better.
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