Assessment of obesity

Children Aged 2 to 18 Years

The Body Mass Index (BMI) for children is calculated in the same way as you would calculate the BMI for adults.  The BMI can be calculated using an online calculator.

However, the BMI is interpreted in a different way for children and needs to be transferred to a paediatric BMI chart to determine whether the BMI is healthy for the child’s age. 

Growth charts can be downloaded and printed from the Royal College of Paediatrics and Child Health website.

Childrens Aged 0 to 2 Years

The BMI cannot be calculated for young infants.  The difference between weight and length centiles can be used to determine whether their weight is healthy for their length.  If the centile for weight is more than 2 centiles higher than the centile for length, this indicates that the infant is overweight.

Growth charts and BMI charts can be downloaded and printed from the Royal College of Paediatrics and Child Health website.