II. Step 1: Calculate Final Height prediction (mid-parental height)

  1. Boy
    1. In: (Father's Height + Mother's Height + 5) / 2
    2. Cm: (Father's Height + Mother's Height + 13) / 2
  2. Girl
    1. In: (Father's Height - 5 + Mother's Height) / 2
    2. Cm: (Father's Height - 13 + Mother's Height) / 2

III. Step 2: Identify Predicted Growth Percentile

  1. Use above predicted mean height to mark growth chart
    1. Mark chart at 18-20 year old mark
    2. Mark Confidence Intervals
      1. Mean Height in inches +/- 2 inches (some use 3.3 inches)
      2. Mean Height in centimeters +/- 5 centimeters (some use 8.3 cm)
  2. Identify growth percentiles for the predicted height

IV. Step 3: Indications for growth evaluation

  1. Child over age 24 months should fall into above percentiles
    1. Growth should at least parallel the 3rd or 97th percentile line
  2. Pursue growth evaluation for any child below minimum or above maximum

Images: Related links to external sites (from Google)