For Example,If your foot length is 25.2cm, choose US size 8. If your foot length is 27.3cm, choose US size 11.
US Size 7 = european 39, foot length is 24.5cm. US Size 10 = european 44,foot length is 27cm. US Size 12 = european 47,foot length is 28.5cm.
Choose the size according your foot length!