Plsase read the following first: NO.1 The size you see is not a standard European or American size, so you need to accurately measure the length of your feet. Then according to your actual length, choose the size according to our size chart. NO.2 The length of the insole should be 0-1.5cm larger than the length of the foot As shown in the picture below, measure your foot length accurately. Size 38 = China Size 38 Fit For Bare Foot Length 24cm Size 39 = China Size 39 Fit For Bare Foot Length 24.5cm Size 40 = China Size 40 Fit For Bare Foot Length 25cm Size 41 = China Size 41 Fit For Bare Foot Length 25.5 cm Size 42 = China Size 42 Fit For Bare Foot Length 26 cm Size 43 = China Size 43 Fit For Bare Foot Length 26.5 cm Size 44 = China Size 44 Fit For Bare Foot Length 27 cm Size 45 = China Size 45 Fit For Bare Foot Length 27.5 cm Size 46 = China Size 46 Fit For Bare Foot Length 28 cm