How to Measure Body Mass Index (BMI) Correctly

Body Mass Index (BMI) is a simple calculation that helps estimate whether a person has a healthy body weight for their height. It is widely used by health professionals to screen for weight categories such as underweight, normal weight, overweight, and obesity.

The formula to calculate BMI is:

BMI = Weight (kg) ÷ Height² (m²)

For example, a person weighing 70 kg and measuring 1.75 meters in height would have:

70 ÷ (1.75 × 1.75) = 22.86

🧮 BMI Categories (WHO Standard)

Underweight: BMI less than 18.5
Normal weight: 18.5 – 24.9
Overweight: 25 – 29.9
Obesity: BMI 30 or more

📏 Tips for Accurate Measurement

Use a calibrated digital scale for weight.
Measure height barefoot, standing straight against a wall.
Enter weight in kilograms and height in meters (or convert).
Always round height to two decimal places for best accuracy.

Is BMI always reliable?

BMI is a good general indicator but does not differentiate between muscle and fat. For athletes or muscular individuals, BMI may overestimate body fat. Complement BMI with other metrics like waist-to-hip ratio or body fat percentage when possible.

→ Use the BMI Calculator