BMI Calculator

How to use BMI Calculator

• Adjust Height: Move the first slider to set your height in centimeters (cm). The equivalent height in feet and inches will be shown as a reference.
• Adjust Weight: Move the second slider to set your weight in kilograms (kg). The equivalent weight in pounds (lbs) is also provided.
• Check Weight Zone: The calculator will calculate your BMI value and immediately identify your health category (Underweight, Normal, Overweight, Obese) along with personalized healthy range suggestions.

What is Body Mass Index (BMI)?

Body Mass Index (BMI) is a medical metric used to evaluate if an individual has a healthy body composition relative to their height. Adopted globally by agencies like the World Health Organization (WHO), BMI is a quick, inexpensive screening tool used to identify potential weight-related issues and health risks.

BMI Calculation Formula

The standard metric formula for calculating Body Mass Index is:

BMI Calculation Example

If an adult weighs 70 kg and is 170 cm tall (1.70 meters):

• Height squared = 1.70 × 1.70 = 2.89 m²
• BMI = 70 / 2.89 = 24.22
• This person has a BMI of 24.2, which falls within the Normal Weight range.

Standard Body Mass Index Categories

The WHO classifies adults over 20 years old into four main weight ranges:

Important Limitations of Body Mass Index

While BMI is highly useful for general populations, it does have key medical limitations:

• Muscle vs Fat: BMI cannot distinguish between muscle weight and fat weight. Athletes or bodybuilders may register as 'overweight' due to pure muscle mass.
• Body Fat Distribution: It does not evaluate where fat is stored (e.g. visceral belly fat, which is riskier than subcutaneous fat).
• Age & Gender: Older adults naturally lose muscle and retain fat, which BMI might underestimate. Women typically have more body fat than men at the same BMI.