The best way to measure your correct size is to compare it to a similar garment you already own.
All measurements in centimeter.

Size Chest Length Sleeve
S 30 cm 40 cm 10 cm
M 34 cm 43 cm 13 cm
L 35 cm 47 cm 15 cm
XL 36 cm 48 cm 15 cm
2XL 38 cm 51 cm 16 cm