US: 10-D to United Kingdom Size 6-B

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).

United Kingdom Size 6-B: Corresponds to a foot length of 24.5 $\text{cm}$ (9.65 $\text{in}$), ball width of 9.6 $\text{cm}$ (3.8 $\text{in}$), acceptable ball width range between 9.3–9.8 $\text{cm}$ (3.65–3.85 $\text{in}$), and fit classification Narrow (7-B / AA).