The (A) measurement in the table is the horse back measurement, not actual rug measurements. To obtain the rug size (EU), measure the horse’s back from the withers to the base of the tail in centimetres (A). 

SizeA Back LengthB Body Length
S95-105 cm145-155 cm
M115-125 cm165-175 cm
L135-145 cm185-195 cm
XL155-165 cm205-215 cm