Specifications The US size here refers to the man’s US . If still not sure, Refer to the UK and EU sizes size: US 4/UK 3.5/Euro 36/22cm US 4.5/UK 4/Euro 36.5/22.5cm US 5/UK 4.5/Euro 37/23cm US 5.5/UK 5/Euro 38/23.5cm US 6/UK 5.5/Euro 38.5/24cm US 6.5/UK 6/Euro 39/24.5cm US 7/UK 6.5/Euro..