How to Calculate BMI or Body Mass Index of a Person?

April 05, 2024

All individuals need to maintain a proper and healthy weight in their bodies. This is because maintaining a proper weight of the body is highly essential to carry out all the physiological functions of the body properly and to build up a strong immune system within the body that will effectively help to protect you from the occurrence of any type of harmful or infectious diseases in the body. In such cases, BMI is a measure that will help you to know whether you are in good health or not and whether you have a healthy body weight. This is indeed a unique measurement of the entire mass of the body of a person. But in some cases, it has also been found that the measurement of BMI can also go wrong, particularly for some groups of people. So, it is very important to get a complete idea about what is all about, what are the steps to calculate the BMI of a person accurately, and most importantly, how can the BMI calculation go wrong for some people, if you were curious about all these questions, this is the right article for you.

What Is All About BMI?

Body mass index or BMI is a measurement of the fat present in your body that is measured based on the height and weight of a person. Though BMI does not directly measure the amount of fat present inside the body of an individual, BMI is a measurement that helps us to get an idea or an estimate about the weight of a person, that often helps doctors and health care experts to understand the condition of health of the person and prescribe medicines to that person accordingly. The BMI or the body mass index of the body also helps to get an idea about whether the person is at all healthy or not. There is a systematic and scientific way to calculate the body mass index of a person and to measure weight and height accordingly. But many times, it has been found that the measure of body mass index is not perfectly accurate to get a proper measurement of the weight of a person’s body. Sometimes there are disparities in the overall weight measurement of a person’s body and the calculations of the body mass index of the same person. When the resulting figure of a person’s BMI increases, then it simply indicates that there is a presence of high levels of fats in the body of that individual. On the other hand, if the BMI figure is on the lower end, then it indicates that the amount of fat present in the body of the person is low. Apart from these, if the BMI of a person is quite high, then it will indicate that the person with a higher BMI figure is more prone to develop several types of health issues, the most important one being obesity, which can result in the occurrence of several types of other adverse health conditions such as risks of cardiac damage, that might lead to the occurrence of diseases such as increased levels of blood pressure, cardiac arrest, heart attack, heart failure, and many other related cardiovascular diseases. Besides, there are chances of developing other conditions as well, such as high levels of blood sugar, causing disorders like diabetes mellitus or type 2 diabetes. But on the contrary, extremely low rates of BMI in an individual is not good at all, because if such conditions arise, then there are high chances of developing severe health-related adversities, such as impairment in the proper body functioning mechanism, diseases like anemia that occur because of low levels of hemoglobin, the weaker immune system of the body, risks of an increase in the fragility of the bones that can eventually result into bone loss, and related health problems. So, it is essential to maintain a proper BMI to stay away from the risks of several types of harmful and infectious diseases.

What Is The Importance Of Measuring BMI?

BMI is an important measurement of body mass and weight that also helps to get an idea about the total fat content in the body of an individual. In fact, to most healthcare experts and medical professionals, BMI is an important screening tool that is very useful and effective for detecting several types of health conditions and adversities in the body of an individual. There are different scales of BMI according to different types of weight. This helps to get a clear understanding of body weight and BMI of the body. For that matter, below is provided such a table that shows the different types of weights and BMI ranges in Kg/m2:

Underweight: Less than 18.5.
Optimum range: 18.5 to 24.9.
Overweight: 25 to 29.9.
Class I obesity: around 30 to 34.9.
Class II obesity: around 35 to 39.9.
Class III obesity: occurs at more than 40.

How To Calculate the BMI Rate Of An Individual?

There is a proper method of calculating the BMI of an individual. Those steps should be followed to reach a number that will become the BMI of a person. The basic steps that will help you to calculate the BMI of a person can be listed here as follows:

First, you need to multiply the body weight of a person in pounds by 703.
Secondly, the result you get after multiplication should be divided by your height in inches (there are 12 inches in a foot).
Now, the final step is to divide this result by the number of your height in inches again. The result you get is your body mass index or BMI.

For instance, if the weight of a person is about 170 lbs. and is 5 feet and 5 inches tall (65 inches total) would calculate their BMI in the following way:

170 x 703 = 119,510.\
119,510 / 65 = 1,838.615
1,838.615 / 65 = 28.28

Thus, the BMI of the person would be 28.2.

How To Know About Your Health Conditions From BMI?

It has already been mentioned that the measurement of the BMI of an individual helps to get an idea about that person’s overall condition of health and body functioning. But some might have confusion about how they would know about the condition of the person’s health from the simple measurement. For this reason, a list can be made with proper classification of the types of body weights according to the BMI levels and the condition of the health of a person. Let us take a detailed look at the table below to understand the phenomena:

BMI range Classification Risk of poor health

less than 18.5 underweight high

18.5–24.9 normal weight low

25.0–29.9 overweight low to moderate

30.0–34.9 obese class I (moderately obese) high

35.0–39.9 obese class II (severely obese) very high

40 or greater obese class III (extremely obese) excessively high

Questions Related To The Accuracy Of Bmi Measurements:

Though BMI helps to measure the weight of an individual, for both children and adults and even helps to get an idea about the health condition of a person, there are cases when the BMI measure is found to become inaccurate. In cases of athletes and people with highly muscular bodies, BMI calculation is often found inapplicable. This happens because BMI measurement can often cause inaccuracy in the measurement of the number of body fats in aged adults and in other individuals, mostly those people who have lost muscle mass. In fact, it has been found in recent studies and research experiments that about 54 million people in the United States of America have been declared to be suffering from obesity or being overweight, but on the contrary other tests such as cardiometabolic measurements are showing that most of those people do have overall good health. It has been found in another study that BMI calculations might go wrong in the case of people such as teenagers, people over the age of 65, people with muscle atrophy, and so on.