BMI Calculator


BMI Metrics

Underweight: BMI < 18.5
Normal weight: 18.5 <= BMI < 24.9
Overweight: 25 <= BMI < 29.9
Obesity (Class I): 30 <= BMI < 34.9
Obesity (Class II): 35 <= BMI < 39.9
Obesity (Class III): BMI >= 40

Calculate Your Body Mass Index By using BMI Calculator Online

BMI, or Body Mass Index calculator, is a online BMI measurement tool that assesses an individual’s body composition by considering their height and weight. Its primary purpose is to gauge the amount of body tissue mass. 

What is the benefit of body mass index (BMI) measurement?

As per the guidelines of the World Health Organization (WHO), Body Mass Index calculator serves as a widely accepted tool for determining if a person maintains a healthy body weight in relation to their height. Specifically, the calculated BMI value is employed to classify individuals into categories such as, 

  • Underweight 
  • Normal weight 
  • Overweight 
  • Obese  

Depending on where your
BMI calculator online falls within predefined ranges the above categories can be defined. These BMI ranges can vary depending on factors like geographical region and age and may include subcategories such as severely underweight or very severely obese. Both being underweight and overweight can have significant impacts on health. Therefore, while Body Mass Index calculator  isn’t a flawless measure of ideal body weight, it serves as a valuable indicator for determining the necessity of additional testing or intervention.  

To check the suitable Body Mass Index (BMI) categories for you displayed by the calculator, please consult the table below 

BMI values for adults 


BMI Range- Kg/m2 

Severe Thinness 

< 16 

Moderate Thinness 


Mild Thinness 

17 – 18.5 


18.5 -25 


25 -30  

Obese Class I 

30 – 35 

Obese Class II 

35 – 40 

Obese Class III 

> 40 

BMI values for children and teens, aged 2-20 


Percentile Range 

Under Weight  


Healthy Weight  

5% – 85% 

At risk of overweight  

85% – 95% 



Body Mass Index (BMI) formula:

Here are the formulas utilized to compute BMI in both the International System of Units (SI) and the US customary system (USC). 


Weight in Kg and height in meter :
BMI = weight (kg) / (height(m))^2   Kg/m2

Weight in lbs and height in inches:
BMI = 703 × weight (lbs) / height^2 (in)   kg/m2

Weight in kg and height in feet and inch:
BMI = Weight (kg) / ((Height (ft) * 0.3048) + (Height (in) * 0.0254))^2   kg/m2

Weight in kg and height in cm:
BMI = Weight (kg) / (Height (cm) / 100)^2   kg/m2

Weight in lbs and height in meter:
BMI = Weight (lbs) * 0.453592) / (Height(m))^2   kg/m2

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