Runs smaller than their other sizesThe fit was fine for my 35 pound Frenchie. The dog, however, was not sure about the entire ordeal.Poor thing, she spends her life searching for blankets and people from whom to leach heat. Being a hairless dog in New England isn't easy. We've been buying shirts and coats for her, of course, but this was the first full-body suit we tried. At first, as expected, she was a little annoyed by the new feeling of something on her legs, but it wasn't long before she realized the newfound freedom of wearable warmth! Now she waits patiently for us to put it on in the morning (none of her previous "mouthing" in protest) and even lifts her legs to help. It helps that the material has plenty of stretch, which aids in the process. We bought two more to rotate in. To be fair, she looks ridiculous, but as a hairless dog, that's nothing new. The one thing I would say is that the color is more brown than green in person, which isn't my personal preference but isn't worth returning it over.Calvin is approximately 13 pounds and the medium fit nearly perfectly (more on the snug side but I was concerned the next size up would be too big). And now that it went through the washer and dryer it has shrunk some (oops, probably should have air dried it). It still fits, just a little more rear hanging out and it's like very short sleeves now. I don't particularly like the neck line, but that's just me. It is a decent item of clothing, appears well made. Cal does prefer the Fitwarm turtleneck, though. Pictures are before it was washed.Bought this for my 17 pound Jack Russell. This is super soft, stretchy, and nice quality material. The only negative I would have to say is that you’d definitely need to size up. Ended up having to get him a large. Other than that, really nice purchase.Everything about Fitwarm clothing is top drawer quality. The stretch stitching is sturdy and designed like a top quality fitted hotel luxury fitted sheet. Strange analogy I know, but it was my first impression when I noticed the quality of the fabric craftsmanship of these products. You won’t be disappointed however I always order up a size.These are the cutest and softer pajamas for my 7 lb pup. Chart is true to size. My girl has a long body and they fit perfectly. Nice quality material. Medium weight I would say. The mauve color is so pretty. Very nice but……my pup hates them ☹️??Love this, looks great on my dog. Brought L to make sure it wasn’t tight.