How to measure the dog size? Chest: measure the thickest part of the chest, add 2-3CM 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: This dog clothes is for small toy dogs or cat under 20 pounds Size XXS: Neck: 17cm/6.5inch; Back: 11cm/4.5inch; Chest: 22cm/8.5inch; for weight 0.55-1.3 pounds/0.25-0.6 KG Size XS: Neck: 20cm/8.0inch Back: 16cm/6.0inch Chest: 27cm/10.5inch; for weight 1.4-2.6 pounds/0.65-1.2 KG Size S: Neck: 23cm/9.0inch Back: 20cm/8.0inch Chest: 32cm/12.5inch; for weight 2.7-4.4 pounds/1.25-2.0 KG Size M: Neck: 26cm/10inch Back: 25cm/9.5inch Chest: 37cm/14.5inch; for weight 4.4-6.6 pounds/2.0-3.0 KG Size L: Neck: 29cm/11.5inch Back: 30cm/11.5inch Chest: 42cm/16.5inch; for weight 6.6-9.4 pounds/3.0-4.25 KG Size XL: Neck: 32cm/12.5inch Back: 35cm/13.5inch Chest: 47cm/18.5inch; for weight 9.4-13 pounds/4.25-6.0 KG Size XXL: Neck: 35cm/13.5inch Back: 40cm/15.5inch Chest: 52cm/20.5inch; for weight 13-19.5 pounds/6.0-9.0 KG Breed recommend:(for reference only): Teddy or Poodle Adult dogs: sometime take M, L, XL Chihuahua Adult dogs: sometime take XS, S or M Pomeranian Adult dogs: sometime take S or M Miniature Schnauzers Adult dogs: sometime take L or XL The recommend weight is just for reference, please kindly take a measurement of your dog before buy, thanks.