US: 5-2A to United Kingdom Size 7-AA

US: 5-2A: Corresponds to a forefoot ball width of 7.9 $\text{cm}$ (3.1 $\text{in}$), ball width range of 7.7–8.1 $\text{cm}$ (3.05–3.2 $\text{in}$), reference foot length of 21.9 $\text{cm}$ (8.6 $\text{in}$), and fit classification Narrow (5-2A / A).

United Kingdom Size 7-AA: 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).