US: 12 to Europe Size 41

US: 12: Features a foot length of 27.6 $\text{cm}$ (10.85 $\text{in}$), ball width of 10.3 $\text{cm}$ (4.05 $\text{in}$), heel height of 5 $\text{cm}$ (2 $\text{in}$), and Flat-to-Medium Arch support optimized for women’s footwear.

Europe Size 41: Features a foot length of 25.9 $\text{cm}$ (10.2 $\text{in}$), ball width of 9.7 $\text{cm}$ (3.82 $\text{in}$), and heel height of 7.5 $\text{cm}$ (3 $\text{in}$), and Medium Arch support optimized for women’s footwear.