Healthy and Active Kids


Children & Youth BMI Calculator

BMI is short for Body Mass Index. BMI is a score that tells you whether your weight is in a healthy range - but it's only one way of measuring if you're overweight. If you're worried about your weight, talk to your parents, teacher or other grown up. A doctor (general practitioner or paediatrician), dietitian or other health professional can give you more information.

BMI is worked out by dividing your weight in kilograms (kg) by your (height in metres)2.

Healthy BMI figures for children and young people are different from those for adults and can be worked out using the calculator below.

For adults over 18, a healthy BMI is between 18.5 and 25. A result below 18.5 indicates that you may be underweight. A figure of or above 25 indicates that you may be overweight. (World Health Organisation figures 2000). Adults can calculate their BMI using the Adult BMI Calculator.

Fill in the Children & Youth BMI calculator below to find out your Body Mass Index and get information about healthy weight ranges. It should be noted that this calculator is only one way of rating BMI levels - other methods may give different results. .

BMI Calculator


Age (yrs)  

Weight (kg)  

Height (cm)  

BMI Value  


The information provided by this calculator is based on data from: Establishing a standard definition for child overweight and obesity worldwide: international survey Cole, T. J, Bellizzi, M. C, Flegal, K. M, Dietz, W. H. BMJ 2000 320: p. 1240-1240. This standard is only one way of determining BMI values and should not be used for clinical purposes.