How to Size Kids Based on Weight

Kids grow at different rates at different points in their lives. When doctors measure height and weight during an annual checkup, they look as much for steady growth trends as they do for a percentile.
However, if you are concerned, or even just curious, about your child's size in between well visits, it can be reassuring and helpful to figure out what size they should be compared with what size they actually are. Interim checking can also help you identify when you need to make small corrections throughout the year.

Things You'll Need

• Child's birth date
• Child's height
• Child's weight
• Kids BMI Calculator, http://kidshealth.org/parent/food/weight/bmi_charts.html

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Instructions

Instructions

• 1

  Weigh your child without him wearing shoes or heavy clothing, such as a sweat shirt or jacket. This will provide a true body weight that does not include the weight of the clothes.

• 2

  Measure the height of your child with his shoes off. Make sure your child is standing straight and with his feet together.

• 3

  Enter gender, birth date, date of measurements, height, and weight into the fields in the Kids Health calculator.

• 4

  Click Calculate BMI.

• 5

  Review the BMI and percentile in the Results section. BMI is a ratio of height and weight. It is reported as an actual number as well as a percentile. The percentile helps you compare size with other kids of the same age and gender. A percentile of 5 percent or less typically indicates the child is underweight, and a percentile of 85 percent or greater typically indicates the child is overweight. However, keep in mind that a child who has had a steady trend of being in the 90th percentile can be healthy and right on track.

• 6

  Compare the BMI plotted on the growth chart as a colored dot with the healthy weight range marked in green. This will give you an idea of the average size of kids of the same age and gender.