How to Calculate Height and Weight Percentiles for Boys

The medical establishment has a predetermined way of measuring children's height and weight against other children in their age group. This is the percentile rule. A child who is in the 50th percentile in weight is mid-range for the age-specific grouping. This means counting all the children in that group, 49 percent are heavier while 49 percent are lighter. The same is true for height percentiles.

Things You'll Need

• Scale
• Measuring Tape
• Growth and development chart

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Instructions

• 1

  Your child should be without shoes and have minimal clothing to allow for accurate height and weight results. Prepare your child prior to this procedure so they are not alarmed. Inform them of what you intend to do and that it will be pain-free.

• 2

  Have the child step onto a balanced scale (that reads zero). Follow the scale's manufacturer instructions on proper use. After the scale has leveled off and is settled on a weight, document that weight.

• 3

  While placing his back against the wall, make sure the child's heels are flat and his spine is erect. Observe that his head is facing forward, with no angles up sideways or down. Use measuring tape to measure from the ground to the top part of the head. Document your height measurement.

• 4

  Refer to the growth chart. Two different charts are used depending on the child's age. One is from the World Health Organization and is used for children 0 to 2 years of age, the other is by the Center for Disease Control for children ranging in age from 2 to adult. See Resources for these charts.