Development of Grading Rules and Application Methodologies for Male Y-shaped Upper Garments Based on Anthropometric Analysis

Han J. M.¹, Lee H. J.¹, Choi H. E.¹,²^†

1 Department of Fashion and Textiles, Seoul National University, Republic of Korea

2 Research Institute of Human Ecology, Seoul National University, Republic of Korea

Introduction

Apparel grading is a critical process for achieving production efficiency and quality standardization (Marniati, 2020). The current apparel industry predominantly relies on simple proportional grading, which fails to account for the unique shape variations inherent in different body types. This limitation results in inappropriate fit as sizes increase or decrease, constituting a primary source of consumer dissatisfaction (Islam et al., 2020). Therefore, to preserve the fit and design intent of the base size, it is essential to establish precise grading values that reflect individual body characteristics. This study focuses on the male Y-shaped body type, for which conventional grading methods are particularly limited, to derive upper-garment grading rules optimized for the specific anthropometric traits of each size group. Furthermore, a practical grading methodology is proposed based on detailed size-specific anthropometric changes, intended for immediate application in the industrial field.

Research Method

This study utilized anthropometric data from a total of 776 individuals by integrating 200 Y-shaped body type datasets obtained from Special Forces measurement data with 576 Y-shaped body type datasets from the 8th Korean National Anthropometric Survey (KATS, 2021). Sizes were categorized at 50mm intervals for chest circumference and height, and size intervals with a frequency of 0.5% or higher were defined as ‘valid size’. Among these, the 'base size' was defined as the most frequently occurring category of the total distribution. The measurement variables consisted of eight key parameters for upper garment construction, including circumference (chest, waist, hip, and upper arm), width (shoulder and neck), and length (top length and arm length).In addition, to reflect segment-specific variations in anthropometric measurements according to size changes, selected variables were further subdivided for detailed analysis. Specifically, chest circumference was divided into front, side, and back chest; top length into armscye depth, waist length, and hip length; and arm length into upper arm and forearm lengths(Figure. 1).

Subsequently, one-way ANOVA and post-hoc tests were performed to verify statistical differences between sizes and to calculate proper grading values. In instances where a specific size overlapped multiple subsets during the post-hoc analysis, it was assigned to the higher size group to ensure a minimum ease allowance, thereby establishing definitive boundaries between groups. Grading values were calculated based on the mean values of the base size and the maximum size within each group. The grading value for chest circumference, which serves as the primary criterion for size group, was set at 50 mm, while the remaining measurement parameters were standardized at 5 mm intervals in order to enhance productivity and efficiency in industrial manufacturing. Based on the analyzed data, a precise grading methodology for practical application was proposed. To validate the proposed grading method, 3D simulations were conducted using CLO 3D, focusing specifically on length-related measurements.  The base size (100–175) was compared with the minimum (100–165) and maximum (100–185) sizes within the same chest circumference condition. The evaluation criteria for length measurements were defined based on the fit characteristics of the base size. In the base size (100–175), the garment waistline aligned with the body waistline, while the sleeve bend line was positioned 22.1 mm below the anatomical elbow line, reflecting upper limb joint movement(Figure. 2).

Result & Discussion

The results of the analysis are as follows. First, a population distribution analysis based on chest circumference and height derived 41 sizes, of which 28 were classified as valid sizes (frequency ≥ 0.5%). The 100-175 size, representing the highest population frequency (13.1%), was selected as the 'base size.' Furthermore, representative sizes for each chest circumference were determined to provide the reference for deriving all grading values(Table. 1). Second, statistical comparisons between the base size and the representative sizes for each chest category confirmed significant differences in all measurement items through ANOVA (p < 0.05). The analysis revealed that the waist and hip circumferences of the Y-shaped body type datasets showed non-linear deviations. Consequently, it was confirmed that applying fixed chest grading values to the waist and hem—as is typical in conventional grading—leads to inappropriate fit outcomes, with garments becoming excessively small for smaller sizes and overly large for larger sizes; therefore, grading values were recalculated to reflect part-specific variances. For width parameters (shoulder and neck), minimal differences(p<0.05) between adjacent sizes suggested that grading efficiency could be achieved through grouping. Notably, the lack of significant variance between sizes 95 and 100 provides a logical basis for a 'zero-grading' approach, maintaining identical pattern dimensions for these parameters. Furthermore, within the same chest sizes, sleeve length showed more distinct variations across height labels than the top length (HPS to hip), proving that sleeve length is a more critical variable than top length for height-based grading. Third, a new grading methodology was derived by considering the rate of change in detailed components. Analysis of chest circumference components showed that in sizes (95, 105) adjacent to the base size, the rate of change in side width was dominant, accounting for 76.4%–82.4% of the variation. However, toward extreme sizes (90, 115), variation in front and back interscye widths increased, with changes in the front interscye width being particularly prominent. For upper-garment length parameters, variations in armhole depth across height categories within chest size 100 were minimal; therefore, grading was primarily based on HPS-to-waist length and hip length. Grading ratios for changes in high-waist and hip lengths were applied at 1:1 for smaller height categories (165 and 170) relative to the base size, and at 3:1 for the larger height category (185). Finally, a differentiated ratio for upper and lower arm length (e.g., 62:38 at 170 cm) was proposed for sleeve grading.

To verify the suitability of the proposed grading methodology, a virtual fitting evaluation was conducted focusing on length-related parameters, which enable intuitive observation of dimensional changes. The results showed that, when graded using the proposed method, the positions of the garment waistline (0 to +1.3 cm) and sleeve elbow line (+2.1 to +2.3 cm) were consistently maintained relative to the body reference lines defined at the base size. In contrast, the conventional grading method showed substantial deviations from the corresponding body reference lines (waistline: −3.8 to +3.2 cm; sleeve elbow line: +1.3 to +4.0 cm). These results indicate that the proposed method preserves both pattern construction intent and ergonomic functionality by maintaining the sleeve elbow line at the same relative position as the base size(Figure. 3). 

Conclusion

This study established a specialized upper-garment grading methodology for male Y-shaped body types, departing from conventional grading through data-driven precision analysis. The detailed size-specific change rates and differential grading ratios derived from this research enabled pattern construction that reflects size-specific body shapes, rather than merely scaling dimensions according to uniform grading rules. Measurements with minimal individual variability, such as neck width and armhole depth, were held constant, while top length grading was conducted by proportionally distributing grading values relative to the waistline. Additionally, sleeve-length grading values were redistributed by dividing the sleeve into upper and lower arm segments. It can be readily integrated into existing CAD-based systems by modifying grading rule tables without altering current workflows. Furthermore, the method is expected to improve fit satisfaction for Y-shaped consumers while maintaining both aesthetic balance and functional mobility, and can be applied to the development of Special Forces garments.

References

Islam, M. M., Jalil, M. A., Parvez, M. S., & Haque, M. M. (2020). Assessment of the Factors Affecting Apparel Pattern Grading Accuracy: Problems Identification and Recommendations. Tekstilec, 63(3).

Korean Agency for Technology and Standards. (2021), Korean agency of anthropometric survey, technology and standards. Size Korea. Retrieved January 05, 2026, from http://sizekorea.kats.go.kr/

Marniati, M. (2020). Comparative Study of Construction/Flat Patterns and Grading Patterns Application in Clothing Making: A Case Study on Women’s Clothing Practices. International Journal for Educational and Vocational Studies, 2(12).