United Kingdom Size 8-B to US: 10-D

United Kingdom Size 8-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).

US: 10-D: Corresponds to a foot length of 27.2 $\text{cm}$ (10.71 $\text{in}$), ball width of 10.4 $\text{cm}$ (4.09 $\text{in}$), acceptable ball width range between 10.1–10.7 $\text{cm}$ (3.98–4.21 $\text{in}$), and fit classification Standard Width (10-D / M).