Size is XL but is for pups of up to 45lbs. Sadly, my dog is closer to 60lbs and this never fit her. See additional photos for more measurement information About Little Beasts: Our sweaters are loved by humans, dogs, and cats around the world. These sweaters are perfect for dogs who might get a bit chilly indoors with the A/C on or for those cool walks outside. We made these for small dogs, medium dogs, and some bigger dogs too. You won't find these dog sweaters anywhere else! https://littlebeast.co/collections/dog-sweaters