My little girl is 12 lbs and looked great in a medium of this dress.Love this dress, so pretty, looks like a pink princess dress! There’s a soft layer of fleece inside the dress that keeps my dog warm during the cold weather. My dog weighs around 7-8lbs, she’s a little less than 12” long and her chest circumference is around 17” (depending on her hair/fur length). I got her a size medium and it fits her very nicely at the chest and the length is perfect (the back length ends a little before where her tail starts). The arm holes are a bit large for her, but that’s fine since her fur will grow out and fill up the space :) Overall, a high quality dress worth for the price!This dress was worth getting. It is very well made and adorable. The color is exactly the same as advertised. My dog lives to be naked but she is always cold too so the fleece lining made her very comfortable. She is a Chipin (chihuahua/miniature pinscher) and the size small fit her very well. Because it doesn't have a leash ring on it I was able to fit her harness on under her dress and it still wasn't tight on her.Cute! Love it but I should have purchased a size small for my 8 pound Maltese. As you can see it’s long on her. I also wish it had an opening for her harness. It’s thick and warm and she was ready to run outside with it lolMy dog was not to happy with me but I thought she looked adorable. It fits great and is good quality I am very happy with this purchase.Love, LoVe, LOVE the SNAPS instead of Velcro! The fleece inner lining is so soft. It’s perfect dress for my girl.Loved the doggie dres was supper cute on our dog.She is going to look so beautiful at my wedding, even though she's not that excited about wearing it.