AI Size and Fit Recommendations

Clothing size labels are not universal measurements. A “medium” can differ across brands, regions, garment cuts, materials, and intended fit. Size-and-fit recommendation systems try to estimate which available size may suit a shopper. They may use body measurements, height and weight, brand-specific size charts, garment measurements, customer feedback, purchase history, and return reasons. Each input has limits, and the meaning of “fits well” depends on the shopper’s preference and use. Research on fashion e-commerce has explored predicting size and fit from customer and product information, including systems that use fit feedback and purchase data. These studies show possible modeling approaches, but a result on a proprietary dataset does not guarantee performance for another retailer, product category, or population. A system may learn that a size was kept, yet a shopper may have kept it because returning was inconvenient. Review text may say “runs small,” but refer to a different style or batch. A recommendation should be treated as decision support. Show the shopper the source of the suggestion where possible: brand chart, item measurements, fit preference, or prior fit feedback. Let people adjust preferences, compare adjacent sizes, and decline to provide personal measurements. Avoid inferring sensitive body characteristics that are not necessary. Explain uncertainty when the model has little data, especially for new brands, unusual cuts, and customers outside the system’s experience. Evaluate fit quality directly rather than optimizing only for conversion. Collect structured feedback such as too tight, too loose, or as expected; separate fit-related returns from color, quality, and delivery issues. Test performance by brand, size range, garment type, and relevant body groups, while respecting privacy. Monitor whether suggested sizes reduce returns without suppressing purchases from underrepresented shoppers. A useful system helps compare evidence and gives people control; it does not promise that a garment will fit perfectly.