US: 18-20 to United Kingdom Size 8-10
Cross-market women’s skirt conversion mapping 18-20 specifications into 8-10.

Analyzing Women’s Skirt Size Equivalence Across Markets
US: 18-20: Waist range of 91–99 (35.8–39 ), hip range of 117–125 (46.1–49.2 ), lengths (Mini/Midi/Maxi): 51/84/109 (20.1/33.1/42.9 ), and fit style Fitted Waist / A-Line & Straight.
United Kingdom Size 8-10: Waist range of 65–69 (25.6–27.2 ), hip range of 91–95 (35.8–37.4 ), lengths (Mini/Midi/Maxi): 43.5/76.5/101.5 (17.1/30.1/40 ), and fit style Fitted Waist / A-Line & Straight.