I debated what size to order, small or medium. I wanted blue, but it was out of stock in medium, so I ordered blue in small and black in medium, thinking I’ll return one. I’m 5’6’, weigh 142 pounds, and am small chested. I was pleasantly surprised that both sizes fit and I like the shirt so much that I decided to keep both! The medium is my preference, as I like looser fitting shirts, but the small really isn’t that clingy and the arm length is fine. I prefer short sleeves for exercise, so I wear these as every day shirts. They’re very comfortable. I don’t often wear long sleeves cuz I’m typically always hot, but these are nice and cool, and if it’s chilly out, a fleece fits perfectly over top and is just enough to keep me warm. I love these shirts and especially the verse!