The back of the waistcoat has an elastic strap to attach and adjust up to 27 cm more! It is extremely stretchy.
So you can add as much to the waist as you need to make it comfortable.

Around the neck there is an adjustable collar so the length of the waistcoat can be optimized for your size.

Clothing measurements:

CM
S: 94 cm waist/ 52,5 cm length. The waist is very adjustable.
M: 95cm waist/ 53cm length. The waist is very adjustable.
L: 98cm waist/ 54cm length. The waist is very adjustable.
XL: 100 cm waist / 54 cm length. The waist is very adjustable.
XXL: 102cm waist / 55 cm length. The waist is very adjustable.
XXXL: 108 cm waist/ 56cm length. The waist is very adjustable.

INCHES
S: 37 inches waist/ 20,5inches length. The waist is very adjustable. 
M: 37inches waist/ 21inches length. The waist is very adjustable. 
L: 38inches waist/ 21inches length. The waist is very adjustable. 
XL: 39 inches waist / 21 inches length. The waist is very adjustable.
XXL: 40inches waist 21.5 inches length. The waist is very adjustable.
XXXL: 42inches waist/ 22inches length. The waist is very adjustable. 

The waist is measured at the smallest point, and the length is from the top of the shoulder to the bottom hem.