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BMI Calculator

Calculate your Body Mass Index (BMI) to check if you're underweight, normal weight, overweight, or obese

kg
Weight in kilograms (e.g., 70.5)
cm
Height in centimeters (e.g., 175)
years
📋 Quick Examples:

Understanding BMI (Body Mass Index)

📊 Global BMI Categories

  • Under 18.5 Underweight
  • 18.5 - 24.9 Normal weight
  • 25.0 - 29.9 Overweight
  • 30.0+ Obese

🧮 BMI Formula

BMI = Weight (kg) ÷ Height² (m²)

BMI is calculated by dividing your weight in kilograms by your height in meters squared.

Example: 70kg ÷ (1.75m)² = 22.86

⚠️ Important Limitations of BMI

  • Muscle Mass: BMI does not distinguish between fat and muscle. Bodybuilders often classify as "obese" despite having very low body fat.
  • Age and Gender: Women naturally have more body fat than men at the same BMI. Older adults tend to have more body fat than younger adults.
  • Pregnancy: BMI is not an accurate measurement during pregnancy.

Complete Guide to Body Mass Index (BMI) & Indian Health Standards

The Body Mass Index (BMI) is a widely used screening tool that estimates whether an individual has a healthy body weight for a person of their height. While it doesn't measure body fat directly, it correlates closely with direct measures of body fat, making it an inexpensive and quick method to screen for weight categories that may lead to health problems.

Global (WHO) vs. Indian/Asian BMI Standards

A crucial factor to understand—especially for users in India—is that the standard World Health Organization (WHO) BMI cut-offs do not always accurately reflect the health risks for Asian populations. Research shows that people of South Asian descent tend to have higher body fat percentages and a higher risk of cardiovascular diseases and type 2 diabetes at lower BMI levels compared to Caucasian populations.

Because of this, health authorities like the Ministry of Health and Family Welfare (India) and the Indian Council of Medical Research (ICMR) recommend modified, stricter BMI cut-offs for Indians:

Category Global (WHO) Standard Indian/Asian Standard
Normal Weight 18.5 - 24.9 18.5 - 22.9
Overweight 25.0 - 29.9 23.0 - 24.9
Obese 30.0 and above 25.0 and above

Health Risks Associated with Abnormal BMI

Maintaining a healthy BMI is crucial for long-term health and wellness. Falling outside the normal range can increase the risk of various health conditions.

Risks of a High BMI (Overweight/Obesity)

  • High blood pressure (Hypertension)
  • Type 2 diabetes and insulin resistance
  • Coronary heart disease and stroke
  • Sleep apnea and respiratory problems
  • Osteoarthritis (a breakdown of cartilage and bone within a joint)

Risks of a Low BMI (Underweight)

  • Malnutrition and vitamin deficiencies
  • Osteoporosis (weak and brittle bones)
  • Decreased immune function and frequent illnesses
  • Fertility issues in both men and women

Frequently Asked Questions (FAQs)

The mathematical formula for calculating BMI is exactly the same for men and women. However, because women naturally tend to have a higher body fat percentage than men, the interpretation of what is "healthy" can sometimes vary in clinical settings. The general categories (Underweight, Normal, Overweight, Obese) apply universally to both genders for adults.

BMI solely relies on height and weight, without distinguishing between muscle mass and fat mass. Because muscle is denser and heavier than fat, athletes and bodybuilders often have a high body weight for their height, resulting in a high BMI (often falling into the "Obese" category) despite having a very low, healthy body fat percentage.

While the formula remains the same, the results for children and teenagers (ages 2 to 19) must be interpreted differently. Instead of strict categories, a child's BMI is compared to other children of the same age and sex using percentile charts. A standard adult calculator should not be used as a final diagnostic tool for children.

How to Use BMI Calculator

1
Enter Weight

Input your current weight in kilograms

2
Enter Height

Input your height in centimeters

3
Optional Details

Add age and gender for context

4
Get Results

See your BMI value and category

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About the Author

B. KUMAR

Founder of Discount Calculator

B. KUMAR is a seasoned developer and retail data analyst with over a decade of experience building custom e-commerce infrastructure and financial calculators. Passionate about consumer rights and digital literacy, he builds tools to help Indians decode complex marketing algorithms and make informed financial decisions.

Calculator Development Financial Utility Tools PHP & JavaScript Development
Last Reviewed: August 2026