How to Check Body Mass Index – BMI Calculator

body mass index

Body Mass Index is an assessment of body fat using your height and weight. It is used to measure body fat using an equation. BMI can help find out if a person has a healthy or unhealthy weight. A high BMI score is an indicator of too much fat in your body. Whereas, a low BMI indicates little body fatness. Moreover, the higher the BMI score, the greater the risk of developing certain diseases. The best part is that you can easily check it using an online BMI calculator.

How to Calculate Body Mass Index

Body Mass Index is a weight in kilograms divided by the square of height in meters. It is a screening tool used to perform health assessments and is calculated using a mathematical formula.  

BMI Calculator – BMI Formula

BMI= weight in kilograms divided by height in meters squared 

= weight (kg) / [height (m)]²

You can also estimate BMI using tables available on the internet. Making the task even easier, you can use an online BMI calculator to automatically generate the BMI along with the interpretations.

BMI Chart – Interpretation

BMI is interpreted using a BMI chart with standard weight ranges. These ranges are the same for men and women of all body types and ages. According to the WHO, a normal BMI falls between 18.5 to 24.9. If your BMI falls somewhere in this range, it shows that you have a normal weight in accordance with your height.

If your BMI falls between 25-29.9 then you are considered overweight, and if it’s greater than 30, then you are considered obese. This means that you have a higher risk of developing chronic health diseases.

The BMI chart that categorizes people as underweight, normal, overweight, and obese as mentioned below. 

Weight Range BMI Score
Underweight <18.5
Normal 18.5-24.9
Overweight 25-29.9
Obese >30

Clinical Relevance of BMI

BMI is used to assess a person’s health risk associated with being obese and overweight. If a person has a high BMI score, they are at risk of type 2 diabetes, heart disease, stroke, high blood pressure, gallbladder diseases, sleep apnea, certain types of cancers, osteoarthritis, lipid disorders, etc.

BMI Correlation With Body Fatness And Lean Body Mass

The BMI highly correlates with body fatness, but even if two people have the same BMI score, their level of total body fat may differ. Even though BMI provides a good measure of obesity, it provides little information on body composition such as muscles, bones, and fat. In short, a high BMI score may be due to high levels of body fatness or high lean body mass.

Very muscular people, with very little body fat, have BMI closer to the overweight category. Heavyweight boxers, weight trainers, and athletes have healthy and fit body composition but their BMI falls into the overweight category. Therefore, BMI is not used for very muscular people as it does not take into account whether the weight is muscle or fat. While BMI can be helpful, it has certain limitations.

Hence, depending on body composition, health care providers assess and interpret BMI accordingly. Do you have any questions regarding the BMI calculator, BMI chart, or its clinical relevance? Let us know in the comments.

Written by Maham Ahmed