B.M.I stands for Body Mass Index. What it does is that it calculates the amount of fat within a person to see if there are healthy or not. The main calculation for B.M.I is simple your weight divided by your height squared as shown in the image below.
When performing the formula, you will get a number, be it a whole number or decimal number. These numbers can be look on at a base chart which will assort each number to its category. Each category is a weight category as shown in the picture below.
Body Mass Index could very well tell you if you're overweight or not. This can be very helpful towards mediocre people as it is more geared to natural growth. What I mean is that B.M.I wouldn't work for athletes because some athletes might be normal height, but also may be muscular. Since muscles weighs more than fat, the weight might be responsible for the wrong reading. Their B.M.I would make them look obese or overweight, but their actually fit. This proves that B.M.I are meant for ordinary people. But sometimes B.M.I aren't very accurate, such as when two people are the same height and weight but one of them is healthy and fit while the other one is unhealthy and fat as shown in the picture below.
It may be harder for you to calculate it and actually find out if you're overweight or obese, so follow this link to go to another website which will contain a B.M.I calculator. To go to that page, click here
To go to that page, follow this URL; http://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm