US: 8-D to United Kingdom Size 6-AA

US: 8-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).

United Kingdom Size 6-AA: Corresponds to a foot length of 23.8 $\text{cm}$ (9.35 $\text{in}$), ball width of 9 $\text{cm}$ (3.5 $\text{in}$), acceptable ball width range between 8.8–9.2 $\text{cm}$ (3.45–3.6 $\text{in}$), and fit classification Extra Narrow (7-3A / AAAA).