Petite Paws Cotton Tee: Small Dog Clothes for Indoors/Summer with Soft Fabric Can be a Halloween costume or indoor shirts for dogs who easily gets hot Measurements XS- back is 7.87 in; chest is 11.81 in (teacup yorkies; 3-6 lbs) S- back is 9.84 in; chest is 13.78 in (puppies, toy poodle, maltese, shihtzu,chihuahua, yorkie, mini pinscher, pomeranian; 6-8 lbs) M- back is 11.81 in; chest is 15.74 in (maltese, shihtzu,chihuahua, yorkie, mini pinscher, pomeranian, bichon frisé, papillon, maltipoo, toy poodle; 8-10 lbs) L- back is 13.78 in; chest is 17.72 in; (maltese, shihtzu,chihuahua, yorkie, mini pinscher, pomeranian, bichon frisé, papillon, maltipoo, toy poodle; king charles cavalier; pug; boston terrier; havanese ; 10-14 lbs) XL- back is 14.75 in; chest is 19.69 in; (maltese, shihtzu,chihuahua, yorkie, mini pinscher, pomeranian, bichon frisé, papillon, maltipoo, toy poodle; king charles cavalier; pug; boston terrier; havanese; most terriers; 14-20 lbs) 2XL- back is 17.72 in; chest is 21.65 in; (maltese, shihtzu,chihuahua, yorkie, mini pinscher, pomeranian, bichon frisé, papillon, maltipoo, toy poodle; king charles cavalier; pug; boston terrier; havanese; most terriers; 20-25 lbs)