How to Calculate Your Body Mass Index: Calculate BMI

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  • Category: Health
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How to Calculate Your Body Mass Index: Calculate BMI

The BMI is widely regarded as a valid reference point for determining whether or not an individual is within a healthy weight range. It is so widely used for gauging bodyweight in reference to wellbeing that health insurance companies use the equation in order to calculate what your rates should be, meaning that they deem a person’s body mass index as being directly correlated with what kinds of health issues an individual is prone to fall ill to.

Most health care practitioners chant, “attain a healthy BMI”, like a mantra to their heavier patients who fall outside the parameter of what is accepted as a healthy weight according to this chart. Here's how to calculate your BMI.

The Equation

BMI = {Weight in Pounds / (Height in Inches) x (Height in Inches)} x 703

A healthy BMI for women is between 19.1 and 25.8. The range for men is from 20.7 to 26.4.

Example of how to calculate BMI

This particular example of a calculation is for a woman who is 5’8 and 135 pounds.

1. Measure yourself; take your height and weight. Make sure that you have no clothes or shoes on during either measurement.

2. Convert your height to inches.

For example, 5 foot 8 inches in height would become 68 inches:
5 feet x 12 (inches per foot) = 60 + 8 = 68 inches

3. Take your height in inches and square that number.

To carry on from the example above, this would be 68 x 68, or 4,624.

4. Divide your weight in pounds by the number that you reached by squaring your inches in height.

135 (weight in lbs) / 4624 (inches squared) = .029195502

5. Multiply the resulting number by 703 to calculate your body mass index.

703 x .029195502 = 20.52

This particular female individual who is 5’8 and 135 pounds would have a healthy BMI of 20.52.

Issues with using the this formula as a gauge of healthy bodyweight.

Calculating your BMI is a good way to get a very general idea of where you fall in terms of healthy bodyweight, however, there are many important factors that this equation doesn’t consider.

For example, someone could have a number that classifies them as being overly heavy when in fact they are perfectly healthy and far from having too much body fat. This is because the measurement doesn’t take into account things like muscle mass, body fat percentage, or bone density.

On the flip side, there is such a thing as a thin “fat” body type. For example, you can be within a healthy BMI range and still have excess body fat – this can be especially unhealthy if you carry that extra weight in your midsection.

BMI calculations are a good place to start when it comes to a general assessment of where you may fall on the healthy body weight spectrum, but they are definitely not a complete, comprehensive tell-all resource. A combination of this calculation, body fat percentages (submersion body fat percentage tests are most accurate), cardiovascular fitness thresholds, and other related health assessments provide the most comprehensive snapshot when it comes to measuring or determining ideal bodyweight for each individual.

Check out these Fitness Blender workout videos to drop body fat