Instructions

• 1
  You can use a floor scale or a home pediatric scale to weigh your baby.scale image by jedphoto from Fotolia.com
  
  Remove the baby's clothes and diaper. Place the child on a weight scale in the sitting position. If the baby is unable to sit, weigh yourself and the baby at the same time. Next, weigh yourself to determine your body weight. Subtract the combined weight from your body weight to determine the child's mass.
  
  
• 2
  Use a soft measuring tape to increase measuring accuracy.Glass with measuring tape. image by mashe from Fotolia.com
  
  Lay the baby down on a flat surface. Measure the baby's length by placing the end of the measuring tape on the top of the child's head and extending it vertically to the heel.
  
  
• 3
  Measure the head circumference around the largest part of the skull.mesure image by sylbohec from Fotolia.com
  
  Measure the circumference of the baby's head by placing the measuring tape around the largest area of the head, usually just above the eyebrows, and continuing around the back of the skull.
  
  
• 4
  Use a calculator for quick number conversions.Calculator image by Alhazm Salemi from Fotolia.com
  
  Convert your measurements into metric numbers. Multiply your child's weight in pounds by 0.45359237 to obtain a weight measurement in kilograms. To convert the baby's length and head circumference from inches to centimeters, multiply by 2.54.
  
  
• 5
  Download the Z-score data files to determine your child's growth score.www laptop image by Photoeyes from Fotolia.com
  
  Download the age-appropriate Z-score data files, titled "weight-for-age," "length-for-age" and "head circumference-for-age" from the Centers of Disease Control and Prevention website.
  
  
• 6
  Z-score date files are prepared in spreadsheet format.number background image by kuhar from Fotolia.com
  
  Locate column A of the spreadsheet, titled "Sex." The left-hand column of the chart indicates a value of 1 for boys and a value of 2 for girls. Find your child's age to the closest half-month in column B, titled "Agemos." Follow the appropriate line over to find the metric measurement that matches your child's height or weight depending on which chart you downloaded. Follow the column up to the top to find the child's score. Z-scores are listed horizontally at the top of the spreadsheet and range in value from -2 to +2.
  
  
• 7
  Note that some children are smaller in stature due to genetic inheritance.compared or trainning image by v2 from Fotolia.com
  
  Compare your score to the national average of "0." Scores closest to "0" indicate average growth. Scores in the plus (+) range indicate above average growth. Scores in the minus (-) range indicate below average growth.