Abstract
The propose of this study is to develop the optimal sizing system of ready-to-wear far elementary school boys using a newly invented statistical technique. The body measurements was classified by the method that equalizes the distribution of the subjects using the probability density function, to theoretically systemize a method to determine a size range of ready-to-wear for elementary school boys between 7 to 12 yeiws old. The results were as follows: 1. Height group includes 9 types of heights: 115, 120, 125, 130, 135, 140, 145, 150 and 155. 2. In the case of short children's groups, the variance in bust girth and waist girth is narrow. The people cluster together around the average. The size deviation of ready-to-wear is small. 3. In the case of tall children's groups, the variance in bust girth and waist girth is wide. The people spread widely around the average. The size deviation of ready-to-wear is large. 4. The optimal size system is suggested considering the weight of growth exponent of children according to their respective ages. Clothing companies can selectively choose sizes that meet the target of their brands. 5. It suggests the body sizes chart, which based on their means by the middle size children for each height group, so that clothing companies make use of it.