Women US 5= UK 2.5= Euro 35 = 21.5 cm
Women US 6= UK 3.5= Euro 36 = 22.5 cm
Women US 7= UK 4.5= Euro 37.5 = 23.5 cm
Women US 7.5= UK 5= Euro 38 = 24 cm  
Women US 8.5= UK 6= Euro 39 = 25 cm
Women US 9.5= UK 7= Euro 40 = 26 cm