They fit my Buffy real good (lucky me
) she weights between 5 and 6 pounds chest 13 inches neck to base of tail about 8 inches, but she has real short legs so on dresses and skirts I do have to adjust under the belly or it will drag or she will trip. The shirts 98% of them fit perfect or if need to do some adjusting under on the chest or it will end up real dirty...lol. She is little but chubby and that's with her being on a diet too...lol
My boys NO the shirts all need adjustments they are too big on the chest and adjust so they do not pee on them. Shorts or pants for doggies are very different, your better off looking for a pattern and make them yourself.
My boys weight from 5 to 6.2 pounds, all 3 have different body shapes and all 3 are taller then Buffy but their chest and waist are smaller.
Just get one peace and see how that fits just in case its way too off and you can not make it fit you can return it.
Good Luck!!