Chest: measure the thickest part of the chest, add 1~2CM will be better. (Usually behind the two legs)
Length: Make sure your dog stands properly, not sitting or lying. Measure along the dog's backbone from the base of the neck to 5CM front the base of the tail.
Neck: the girth of the neck, add 2~3CM will be better.

Note: If your dog is a large chest, long hair, or at the high end of the size, you may order the next larger size to ensure a comfortable fit.

Size Details:

Size XS for body 15cm(5.9inch),Chest 25cm(9.8inch),Neck 19cm(7.48inch);

Size S for body 19cm(7.48inch),Chest 30cm(11.8inch),Neck 21cm(8.27inch);

Size M for body 23cm(9.05inch) ,Chest 35cm(13.78inch),Neck 24cm(9.45inch);

Size L for body 28cm(11inch),Chest 40cm(15.75inch),Neck 27cm(10.63inch);

Size XL for body 33cm(12.99inch),Chest 45cm(17.72inch),Neck 30cm(11.8inch);