Aritzia's proprietary sizing system maps a size 8 across its exclusive clothing brands roughly to a medium or a traditional US numeric dress size, though exact measurements vary slightly depending on the specific silhouette, fabric stretch, and tailored design lines of individual items. The retailer provides comprehensive online size guides that detail exact bust, waist, and hip measurements in both inches and centimeters to help shoppers select the ideal fit. Because styles range from structured blazers and fitted contour bodysuits to relaxed-fit loungewear, consulting individual product size charts and customer review feedback is recommended for optimal garment selection.