Size Chart:

28/XS size 62-75 cm

30/S Waist size 78-80 cm
32/M Waist size 81-85 cm
34/L Waist size 86-90cm
36/XL Waist size 91-95 cm
38/XXL Waist size 95-100cm

The measurements apply to the flat shorts, if your waist is about the same size as the flat shorts, take one size larger.