United Kingdom Size 3-AA to US: 9-4A

United Kingdom Size 3-AA: Corresponds to a forefoot ball width of 7.6 $\text{cm}$ (3 $\text{in}$), ball width range of 7.4–7.8 $\text{cm}$ (2.9–3.1 $\text{in}$), reference foot length of 21.9 $\text{cm}$ (8.6 $\text{in}$), and fit classification Extra Narrow (5-4A / Slim).

US: 9-4A: Corresponds to a forefoot ball width of 8.5 $\text{cm}$ (3.35 $\text{in}$), ball width range of 8.3–8.7 $\text{cm}$ (3.25–3.45 $\text{in}$), reference foot length of 24 $\text{cm}$ (9.45 $\text{in}$), and fit classification Extra Narrow (9-4A / Slim).