Calculate Your Body Mass Index

Body Mass Index (BMI) is a estimate of body fat based on height and weight that applies to both adult men and women. We calculate your BMI to get an idea of whether you’re underweight, a healthy weight, overweight, or obese (for your height).

The Body Mass Index (BMI) calculation doesn’t take into account your gender, age, ethnicity or other body composition factors (i.e. it does not differentiate between body fat and muscle mass). For that reason we use your BMI in conjunction with a range of other measures, including blood tests and your neck, waist and arm measurements, to determine your risk of health complications caused by your weight.

Your Body Mass Index (BMI) is calculated by dividing your weight (kg) by your height (metres) squared.

Calculate your BMI

Metric Imperial



BMI Classifications

BMI (adults)

Classification

Less than 18.5

Underweight

18.5 to 24.9

Healthy weight

25 to 29.9

Overweight but not obese

30 to 34.9

Obese class I

35 to 39.9

Obese class Il

40 or more

Obese class Ill

There are some exceptions. The healthy weight BMI range is generally:

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