Body Mass Index Meaning

The Body Mass Index formula is one of the most relevant and widely accepted measures of weight in relation to general health and well-being!

The Body Mass Index table shows figures found by comparing weight to height ratio. The BMI formula is not a perfect tool or measurement that applies in every case. But, you can use it to calculate the best measure of a healthy weight in relation to tallness.

Determining your Body Mass Index means you will have an overall assessment of how well you are doing in the health stakes. Most people do not know their BMI figure, because you may need to use a calculator to work it out. If not, you will need to be able to perform basic arithmetic calculations.

Note: Use the formula or basic Body Mass Index tables of weights and status to get an approximate idea of how well you are doing.

Categories for BMI

There are five standard categories used to assess health risks in relation to obesity, which are:

  • BMI less than 18.5: Underweight (seek advice because it has potential health risks in some cases).
  • Between 18.5 and 24.9 BMI: Considered as ‘normal’ weight.
  • Between 25 and 29.9 BMI: Considered as overweight (address it with corrective action).
  • BMI 30 or higher: Considered as obese (your health is at risk in the short and long term).
  • BMI 40 or higher: Morbid obesity (requires urgent medical help and corrective action).

How to Work Out Body Mass Index

So, how do you find your own Body Mass Index? The calculation used to work out your own BMI is:

  1. Your weight (in pounds) multiplied by 703 [body weight x 703 = x]
  2. Your height (in inches) times two (2) [height x 2 = x]
  3. Divide the first calculation by the answer from the second calculation to get the BMI figure.

An example calculation for working out body mass:

Weight is 171 lbs x 703 = 120,213
Height is 69 x 2 = 4,761
Thus, the Body Mass Index calculation is 120,213 / 4,761 = 25.24
This example would suggest that the individual is a little overweight!

Sample BMI Tables

An individual with a height of 66 inches (or 5 feet 6 inches, or 165 centimetres) would have a height of 4356 (as shown in the BMI table below).

90lbs (40kg) 63,270/4536 = 15 Underweight
110lbs (50kg) 77350/4536 = 18 Normal
130lbs (59kg) 91,390/4536 = 21 Normal
154lbs (70kg) 105,450/4536 = 24 Normal
170lbs (78kg) 119,510/4536 = 27 Overweight
190lbs (86kg) 133,570/4536 = 31 Obese
210lbs (95kg) 147,630/4536 = 34 Obese
230lbs (105kg) 161,690/4536 = 37 Obese
250lbs (114kg) 175,750/4536 = 40 Morbid Obesity

Note: The comprehensive BMI calculation formula shows results in lbs and kilograms for individuals with a height range of 68 to 72 inches.