Europe Size 40 to US: 5
Cross-market women’s shoes, heels, boots, flats, and sneakers conversion mapping 40 specifications into 5.

Analyzing Footwear Size Equivalence Across Markets
Europe Size 40: Features a foot length of 25.4 (10 ), ball width of 9.4 (3.7 ), heel height of 9 (3.54 ), and Universal Arch support optimized for women’s footwear.
US: 5: Features a foot length of 21.9 (8.6 ), ball width of 8.2 (3.2 ), and heel height of 5 (2 ), and Medium Arch support optimized for women’s footwear.