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 51 cm 76 cm 65 cm
M 53 cm 77 cm 66 cm
L 55 cm 78 cm 66 cm
XL 59 cm 80 cm 67 cm
2XL 61 cm 80 cm 69 cm