1. What is BMI?

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in meters (kg/m²).

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters

3. Indian BMI Cutoffs

Indian-specific BMI categories:

• < 18.5 kg/m² — Underweight
• 18.5-22.9 kg/m² — Normal (healthy range)
• 23-24.9 kg/m² — Overweight (at risk)
• 25-29.9 kg/m² — Overweight (obese class I)
• ≥ 30 kg/m² — Overweight (obese class II)

Note: These cutoffs are lower than WHO standards due to higher health risks at lower BMI for Indians.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters. For height in cm, divide by 100 (e.g., 170 cm = 1.7 m). All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why different BMI cutoffs for Indians?
A: Indians have higher body fat percentage at lower BMI and greater risk of diabetes and heart disease at lower BMI compared to Caucasians.

Q2: Is BMI accurate for athletes?
A: No, BMI may overestimate body fat in muscular individuals. Other measures like waist circumference may be better.

Q3: What is the healthy BMI range for Indians?
A: 18.5-22.9 kg/m² is considered healthy for Indian adults.

Q4: Should BMI be interpreted differently by age?
A: Yes, older adults may have slightly higher optimal BMI (up to 23-24) compared to younger adults.

Q5: Are there better alternatives to BMI?
A: For more accurate assessment, consider waist-to-hip ratio, body fat percentage, or other clinical measures.