How this BMI calculator works

Step 1: Enter birth date

We use this to calculate your child’s exact age in months.
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Step 2: Select gender

Gender is needed because growth patterns differ between boys and girls.
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Step 3: Enter height and weight

This information is used to calculate BMI.
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Step 4: Review your answers

Make sure the details are correct before viewing the result.
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Step 5: View result

See your child’s BMI centile and what it means.
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