US: 12-D to United Kingdom Size 7-D

US: 12-D: Corresponds to a foot length of 29 $\text{cm}$ (11.42 $\text{in}$), ball width of 10.8 $\text{cm}$ (4.25 $\text{in}$), acceptable ball width range between 10.5–11.1 $\text{cm}$ (4.13–4.37 $\text{in}$), and fit classification Standard Width (12-D / M).

United Kingdom Size 7-D: Corresponds to a foot length of 25.2 $\text{cm}$ (9.92 $\text{in}$), ball width of 10 $\text{cm}$ (3.94 $\text{in}$), acceptable ball width range between 9.7–10.3 $\text{cm}$ (3.82–4.06 $\text{in}$), and fit classification Standard Width (8-D / M).