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 34 cm 43 cm 38 cm
M 36 cm 45 cm 39 cm
L 39 cm 48 cm 40 cm
XL 40 cm 49 cm 41 cm
2XL 41 cm 50 cm 42 cm