United Kingdom Size 10-E to US: 9-B

United Kingdom Size 10-E: Corresponds to a foot length of 28.4 $\text{cm}$ (11.18 $\text{in}$), ball width of 11.1 $\text{cm}$ (4.37 $\text{in}$), acceptable ball width range between 10.8–11.4 $\text{cm}$ (4.25–4.49 $\text{in}$), and fit classification Wide (11-2E / EE).

US: 9-B: Corresponds to a foot length of 26.2 $\text{cm}$ (10.31 $\text{in}$), ball width of 9.9 $\text{cm}$ (3.9 $\text{in}$), acceptable ball width range between 9.6–10.1 $\text{cm}$ (3.78–3.98 $\text{in}$), and fit classification Narrow (9-B / AA).