BMI Calculator

Knowing your body mass index (BMI) is one of the best ways to establish whether or not you're in a healthy weight range. Use our calculator below to work out your BMI and discover which of our programs is right for you.

Calculate your BMI

Calculate your BMI (Body Mass Index)


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Calculating your BMI: how does it work?

Your weight alone isn't the most reliable indicator of whether or not you're overweight and how many kilos you may need to lose. Body Mass Index (BMI) is a calculation used to estimate your total amount of body fat and determine which category you fall into: underweight, healthy weight, overweight or obese.

Your BMI is calculated by dividing your body weight in kilograms by your height in metres squared (m2). It's a useful working guide for most adults over 18 and can tell you a lot.

The Body Mass Index (BMI) is a statistical measure of body weight based on a person's weight and height. Your BMI is a handy indicator to demonstrate if you are in a healthy weight range.

Exceptions to the BMI Rule

Your BMI is a useful tool, but it's not a foolproof method for everyone. BMI can't distinguish between fat and muscle, so those with greater-than-average muscle mass, such as muscular athletes and bodybuilders, will end up with a high reading while not needing to lose weight.

BMI is also unsuitable for certain populations and individuals, including Aboriginal people, Torres Strait Islanders, Asian people, children, pregnant women and the elderly. For all these reasons, you should treat it as a rough guide to be used in tandem with other body-weight indicators.

Equally, while finding out your BMI is extremely valuable, your waist circumference is also considered an important measure of health risk. That's because carrying too much fat in the abdominal region has been linked to chronic conditions such as diabetes and heart disease.