In this database, weight-for-height, height-for-age and weight-for-age are interpreted by using the Z-score classification system.. Weight-for-age charts, 2 to 20 years, selected weight z-scores in kilograms, by sex and age; ZSTATAGE Cdc-excel [XLS – 188 KB] ZSTATAGE Cdc-excel [CSV . BMI Pediatric Calculator will determine the BMI for children and calculate the Z Score and percentiles based on the age of the child.. The reliability of weight-for-length/height Z scores represented as a Z score for diagnosing acute may limit its interpretation in this age . Standardized Height and Weight Calculator this calculator displays the gender and age specific percentile and Z-score of the measurement.. The Infant Weight for Length through 36 months of age. differences in weight/height. At these extremes, the z-score is a more precise .