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About Body Mass Index

Body mass index, or BMI, is a measurement that calculates weight in relationship to height and is considered a reliable indicator of body fat. For adults (age 20 and older), BMI breakdowns are as follows:

BMI	Weight Status
Below 18.5	Underweight
18.5 – 24.9	Normal
25.0 – 29.9	Overweight
30.0 and Above	Obese

BMI for children and young adults aged 2 to 20 is measured by a gender and age specific charting system known as BMI-for-age. BMI-for-age is expressed in terms of percentiles.

• Underweight – less than 5th percentile
• Normal – 5th percentile to 84th percentile
• At risk of overweight – 85th percentile to 94th percentile
• Overweight – 95th percentile or higher

The following calculator is for adults age 20 and older only. Your child’s pediatrician can help you interpret their weight, height, and BMI patterns based on their age and gender.