How to calculate your BMI (Body mass index)

  1. Divide your weight (in kilograms) by your height (in meters).
  2. Divide the answer by your height again to get your BMI.

So the body mass index formula is as follows:

BMI = weight / height².

Basic BMI ranges

There are five basic ranges within the BMI scale:

Underweight Less than 18.5
Normal weight 18.5 - 24.9
Overweight 25 - 29.9
Obesity 30 - 35
Severe obesity 35 and more