BMI, also referred to as Body Mass Index, is a method used in screening one’s body fat. This is done by measuring the height and weight of a person and converting it into their equivalent BMI. Furthermore, BMI can also determine possible risk factors for a person’s health, should there be any. That being said, it is recommended for people to learn how to calculate BMI, especially if they want to know if their weight is healthy or borderline unhealthy. 

Calculate BMI using a calculator 

Luckily, a calculator can be used to determine one’s BMI. All you have to know is your height and weight, and the formula below. 

Take note, it is not recommended for just everyone to calculate their BMI. The formula may not show accurate results for the following:

  • Pregnant women 
  • Elderly people
  • Young children 
  • Long distance athletes
  • Muscle builders 

The reason behind this is that the BMI of these individuals will differ from those that do not belong in the aforementioned group of people. BMI is not able to determine whether the weight measured is muscle or fat. Take athletes, for instance. They have higher muscle mass compared to those who are not athletes. 

Another example would be pregnant women. Their bodies have a different composition compared to when they were not carrying an infant. That being said, the BMI they end up with is not reliable. So if you fall under the following categories aforementioned and end up having a low or high BMI, do not fret since it is likely inaccurate. 

Formula using Metric System to calculate BMI 

According to the CDC, the formula to calculate BMI using the metric system can be either of the following:

  • Weight (in kilograms) divided by [height(m)]2
  • [weight (in kilograms) divided by height (in centimeters) divided by height (in centimeters)] multiplied by 10,000

Different BMI weight types

After computing your BMI, determine what range you fall into. There are mainly six different BMI weight types:

  • Underweight: >18.5
  • Optimum range: 18.5 to 24.9
  • Overweight: 25 to 29.9
  • Class I obesity: 30 to 34.9
  • Class II obesity: 35 to 39.9
  • Class III obesity: exceeds 40

Take note that a BMI cannot always be relied on for accurate results. Aside from calculating BMI, medical professionals make use of other methods in checking a person’s weight type, such as measuring the circumference of the waist, measuring skin thickness, and using a DEXA scan.

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