BMI calculators


for adults and children

There are a number of factors to consider when evaluating how weight affects your health such as age and body type.

Photo of someone standing on a scaleHowever, calculating your body mass index (BMI) is a quick way to learn whether or not you're at a healthy weight for your height. Use our tool to calculate your BMI and learn what your BMI means.

Calculate your body mass index (adults)*.

Your child's body mass index

This tool uses weight and height to compare your child's size to that of other boys or girls of the same age. Your child's size will be given 2 numbers — a BMI value and its percentile. The percentile is the number that ranks your child's size among other children of the same gender and age.

Not all children are the same. Some are naturally larger and some are naturally smaller. What's most important is that your child is at the same percentile over time, so it takes several measurements to assess your child's growth.

Calculate your child's BMI.

* This tool is not accurate for children under age 18, women who are pregnant or nursing, or the elderly.

Reviewed by: Mark Groshek, MD, April 2016

© 2016 Kaiser Permanente

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