1. What is BMI?

Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. BMI provides a reliable indicator of body fatness for most people.

2. How to Calculate BMI

The BMI formula is:

Where:

• Weight — in kilograms (kg)
• Height — in meters (m)

Example: For a person who weighs 70kg and is 1.75m tall:
BMI = 70 ÷ (1.75 × 1.75) = 22.9 kg/m²

3. BMI Categories

Standard BMI Categories:

• Underweight: BMI less than 18.5
• Normal weight: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• Obese: BMI 30 or greater

Note: These categories may vary slightly for different populations (e.g., Asian populations may have different cutoffs).

4. Using the Calculator

Instructions: Enter your weight in kilograms and height in meters. For height, you can convert from cm to m by dividing by 100 (e.g., 175cm = 1.75m).

5. Frequently Asked Questions (FAQ)

Q1: Is BMI accurate for everyone?
A: BMI is a useful screening tool but doesn't directly measure body fat. It may overestimate body fat in athletes and underestimate it in older people with less muscle mass.

Q2: What's a healthy BMI range?
A: For most adults, a healthy BMI is between 18.5 and 24.9. However, individual factors like muscle mass and frame size should be considered.

Q3: Should children use the same BMI categories?
A: No, children's BMI is interpreted differently using age- and sex-specific percentiles.

Q4: Are there alternatives to BMI?
A: Other measures include waist circumference, waist-to-hip ratio, and body fat percentage measurements.

Q5: How often should I check my BMI?
A: For most adults, checking every few months is sufficient unless you're actively trying to change your weight.