Calculate body mass index (BMI) for children and teenagers
Use this calculator to:
- check the BMI of children and teenagers aged between 2 and 17
- get advice about what to do next
Use this calculator with a parent or carer if you are aged 17 or under.
This BMI calculator does not:
- tell the difference between muscle and fat
- give you a body fat percentage
- take into account the child's ethnic background or physical activity levels
You should not use this calculator to diagnose any conditions. If you are worried about a child's weight or growth, contact the child's health visitor, school nurse or GP surgery.
Who can use this calculator
Use this calculator if the person you're using it for:
- is aged between 2 and 17
- is not pregnant
- has not been diagnosed with an eating disorder, or think they may have one
- does not have a condition that affects their height, or a growth disorder
- lives in the UK
To check the BMI of someone aged 18 or over, calculate BMI for adults.
To check the growth of a child under 2 years old, speak to your GP or health visitor.
What you will need
To use the calculator, you will need to know the child's:
- date of birth
- sex at birth
- height
- weight
You will also be asked when these measurements were taken.
More information on this calculator
By using this calculator you agree to our privacy policy and terms and conditions.
Software Information
Software name
Child BMI tool
Version
5.0.0
Date of release
09/2024
Manufacturer and maintainer
NHS England
7 and 8 Wellington Place
Leeds
West Yorkshire
LS1 4AP
Page last reviewed: 9 September 2024
Next review due: 9 September 2027