Is my child's weight healthy?
Understand your child's BMI-for-age using a recent height and weight measurement.
This calculator is for general educational use and does not provide a diagnosis. A child's growth should be assessed over time with a healthcare professional.
This calculator uses category cut-offs at the 5th, 90th and 95th percentiles, which differ from WHO's published classification.
Enter your child's details
For children aged 2 to 18. Use a recent weight and height, measured without shoes and heavy clothing.
Your child's result
Questions about your child's growth or eating habits? Contact the clinic.
How is BMI used in children?
BMI is calculated using a child's height and weight. In children, BMI changes naturally as they grow, so it is interpreted according to age and sex using a BMI-for-age percentile rather than adult BMI cut-offs.
A percentile compares your child with children of the same age and sex. For example, the 60th percentile means your child's BMI is higher than 60 out of 100 children of the same age and sex.
See it on the growth chart
Please check the numbers
This weight and height give a BMI that is far outside the usual range for a child of this age. Please check that weight is in kilograms and height is in centimetres. If the numbers are correct, please speak to a paediatrician.
What the results mean
Each category is based on where your child's BMI sits compared with children of the same age and sex.
Underweight
Below the 5th percentileBelow the expected range. If you are concerned about your child's growth or weight, speak to a paediatrician.
Healthy weight
5th to below the 90th percentileWithin the expected range. Continue to support healthy eating, regular physical activity and healthy lifestyle habits.
Overweight
90th to below the 95th percentileAbove the expected range. It may help to review growth pattern, diet, physical activity and overall health with a healthcare professional.
Obesity
95th percentile or aboveIn the obesity range. A paediatric assessment can review overall growth and provide health and lifestyle support.
Important: these categories are based on BMI-for-age percentile, not adult BMI cut-offs such as 18.5, 25 or 30.
Growth reference
The calculator accepts ages 2 years 0 months to 18 years 11 months. Its growth-reference tables are based on the WHO Child Growth Standards (2006) through 60 months and the WHO Growth Reference (2007) from 61 months.
