Body Mass Index
Working out your Body Mass Index (BMI) can be a good way to assess whether or not you are within an ideal weight for your height, gender and age. BMI is worked out by taking your weight in kilograms and dividing it by the square of your height in metres. This figure can then be compared with typical results for other people for your height, gender and age. It can be used to check whether you are underweight or overweight.
Example BMI calculation
For example, if your weight is 60Kg and your height is 1.6m, then your BMI would be:
60 divded by (1.6 x 1.6) = 23.4.
For an adult, this is a healthy BMI. It is also a normal weight for a 15 year old girl. But for a 15 year old boy, then this BMI could indicate being overweight (on average girls aged 12-16 have a higher BMI than boys the same age).
It's best to get a professional opinion
You can get inaccurate results if you try to work out your BMI yourself at home, so it's best to ask your school nurse or doctor to do it for you if you feel that you are either underweight or overweight. Alternatively, you can try the online calculator below designed for young people aged between 5 and 17 years old.
BMI results aren't always perfect
Although using BMI can be a good way to estimate ideal weight, there are circumstances where it can give misleading results. For example, a person who plays lots of sport may have a high BMI, but this may be due to muscle rather than fat. If in doubt, speak to your doctor or school nurse.
Related External Links:
- BMI Calculator
This NHS site has a calculator which works for 5 to 17 year olds and can give you an idea of whether you are normal or overweight. (Unfortunately it can't tell you if you're underweight).