Body Mass Index

5.11 Body Mass Index

The first term we need to know is the body mass index or BMI. The body mass index or BMI is the ratio of how tall someone is compared to their weight. The best way to understand this concept is by example. Think about these 3 people:

They all weigh the same, but you can clearly see that person #3 appears quite obese. The taller you are, the more weight you are allowed to carry before being considered obese, which makes sense of course. Now lets calculate the BMI of these three people. Here is the equation:

BMI = [ weight (lbs) / height (in)2 ] x 703

BMI = [ weight (kg) / height (m)2 ]

Here is how the BMI categories break down:

That means that our first example person #1 has a normal BMI of 24.4; person #2 is overweight with a BMI of 29; and person #3 is obese with a BMI of 35.5.

Now how about these three people:

These three people are the exact same height, but have different weights. Doing the same calculation, we see that Person #1 has a normal BMI, person number 2 is overweight, and person #3 is obese.

Here are the categories of BMI. Your goal should be eventually to get into the normal range.

Now lets figure out YOUR BMI. Here is a table showing height versus weight to help you quickly figure out your current BMI. Just line up your height and your weight on this chart and you can get your exact BMI number and category.

BMI Calculator

BMI Calculator


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