US: L to United Kingdom Size 6
Cross-market women’s belt and cinch conversion mapping L specifications into 6.

Analyzing Women’s Belt Size Equivalence Across Markets
US: L: Corresponds to a waist/hip size of 85 (34 ), waist range of 76–86 (29.9–33.9 ), total strap length of 95 (37.4 ), and fit classification Standard Waist / Hip.
United Kingdom Size 6: Corresponds to a waist/hip size of 70 (28 ), waist range of 60–70 (23.6–27.6 ), total strap length of 80 (31.5 ), and fit classification Waist / Snug Cinch.