Body mass index (BMI) calculator

BMI is a measurement that gives you an idea of whether you're underweight, overweight or a healthy weight for your height. Your BMI is calculated using your weight (in kilograms) and your height (in metres) and is best done using a calculator. See the calculator below.

Note: BMI is a useful measurement of growth for most people. However, it is only an estimate and can’t tell you how much of your weight is body fat and how much is muscle mass. Find out more about BMI and what your results mean.

The BMI measurement is not suitable for some people, such as:

• women who are more than 10 weeks pregnant
• children under 2 years of age
• people, particularly children, with certain health conditions, such as some endocrine or genetic conditions.

BMI is also less accurate as an indicator of being overweight in:

• adults with higher than normal levels of lean body tissue (muscle mass). This is because muscle weighs more than fat and the BMI does not take this into consideration.
• people in ethnic groups with smaller body stature (eg, Asian ethnic groups).

If you have any questions or concerns about your results from the following BMI calculator, or about your weight in general, talk to your healthcare provider.