What is Body Mass Index (BMI)?
Body Mass Index (BMI) is a simple calculation based on an individual’s height and weight that provides a general idea of body fat levels. It is a key criterion for objectively assessing a patient’s weight status prior to bariatric (obesity) surgery.
BMI is calculated by dividing a person’s weight (in kilograms) by the square of their height (in meters), using the formula:
BMI = weight (kg) / height² (m²)
The resulting number is classified as follows:
Below 18.5: Underweight
18.5 – 24.9: Normal weight
25 – 29.9: Overweight
30 – 34.9: Obesity Class I
35 – 39.9: Obesity Class II
40 and above: Morbid Obesity (typically considered for surgical evaluation)
You can use this tool to calculate your own BMI and see how far you are from your ideal weight. This is the first step in determining whether you may be a suitable candidate for obesity surgery.
