US: 8-10 to United Kingdom Size 4-6
Cross-market women’s sleepwear conversion mapping 8-10 specifications into 4-6 for nightgowns, pajama sets, and sleep shirts.

Analyzing Women’s Sleepwear Equivalence Across Markets
US: 8-10: Corresponds to a relaxed bust range of 90–94 (35.4–37 ), elastic waist range of 72–76 (28.3–29.9 ), and comfort drape classification Relaxed / Comfort Drape.
United Kingdom Size 4-6: Corresponds to a relaxed bust range of 78–82 (30.7–32.3 ), elastic waist range of 60–64 (23.6–25.2 ), and comfort drape classification Relaxed / Comfort Drape.