To calculate body mass index, you are looking at your weight in relation to height. I will show you the BMI formula to calculate BMI or you can use this reference BMI table where calculating BMI is already done.
The body mass index is a guide used to determine if you are overweight or underweight. It does have its limitations though. Your BMI does not and cannot evaluate your body composition. Let me explain.
Your weight is composed of body fat, tissue mass, water and your bones. Fat tissue is not very dense; lean tissue is denser. Therefore, a fit and active individual or athlete would have lower body fat, her bone density would also be higher which would be reflected in a higher body mass index. Whereas, the sedentary person may be overweight with a normal BMI when also assessing her body composition including bone size and density, body fat and muscle density.
Even a skinny person who has very little lean muscle is physically inactive may fall within the norm on BMI, yet be frequently ill, lacking energy and feel less than healthy. Therefore, consider BMI as part of an overall assessment and not as a stand alone datum. Also consider your bone structure, bone density, muscle density and the fat-fold test to determine the relevance of your body mass index reading.
The formula for calculating BMI is your weight in kilograms divided by your height in meters multiplied by your height in meters. It looks like this…
The formula using pounds is…
Or you can use this BMI Table for a quick reference. Scroll down below the table for a BMI calculator.
Click on the table for larger view of table.