What is BMI?
BMI stands for Body Mass Index. It is tool used to calculate if you are carrying the correct body weight for your height. It is said to estimate the total amount of body fat you are carrying. It does not measure the weight of bones, muscle an organs. The idea of calculating a person’s BMI is to work out if they are a “healthy body weight” compared with their height. The Body Mass Index scale should only be used on full grown adults. This is because it takes into account the weight of bone, muscle and organs. In children who are not fully grown bone density, muscle and organ development is still progression so it is difficult to calculate a BMI.
How to calculate your BMI
BMI is calculated using a simple formula that takes into account your height and overall body weight. The formula is:
[Weight (in pound) / height (in inches) 2] or [weight (in kilograms) / height (in meters) 2]
To calculate your BMI you need to measure your height in inches or meters and you need to measure your weight in pounds or kilograms. You then need to work out your height squared (Your height multiplied by itself). The next step is to divide your weight by your height squared. The number that is the answer is your BMI score. Here is an example
Peter is 180 cm tall and weighs 95 kilograms. He would complete the formula as follows:
1. Peter works out that he is 1.8 meters tall
2. He then squares this number (1.8 x 1.8 = 3.24)
3. Peter then divides his weight of 95 by 3.24 (95/3.24 = 29.32)
4. Peter rounds this number to 29
5. Peter would be considered overweight as anything higher than 25 is overweight.
Using the Body Mass Index a score of 20 or under is considered underweight. 20 to 25 is scored as a good healthy body weight for your height. Whereas a score over 25 is considered to be overweight and over 35 is considered obese.
The Body Mass Index is only an estimate and various other factors need to be taken into account when using the information gained from it. The Body Mass Index tends to overestimate the amount of body fat for high performance athletes, body builders and pregnant women. This is because these people do not have the average weight amounts for bone, muscle and organs for their height. The Body Mass Index also generally underestimates the amount of body fat for the elderly and physically disabled who again will not have the average amounts of weight for bones and muscles.