I am 50 something.. size small in everything. I can size up or down depending on whether I want it a bit looser or tighter. But mostly a small. Soooo.. I ordered the small. Yes, the sleeves are a little short but nothing bad and honestly I have this same top from Lululemon in a small and the sleeves or shorter on that one too. The Lulu one is a little more cottony soft but I haven't washed this one yet but still a nice material and similar fit to the one I have from Lulu and a fraction of the cost. I am a lover of Lulu and Athleta and I am really starting to love some of the amazon brands just about as much.. at a much lower cost. We have myself and 2 teens in the house.. all different sizes.. and amazon is helping me save $$! I am 5'6".. 125-130. Shorter torso, longer legs. Green is adorable! Will go so cute with my Colortopia splinter camp leggings. I am keeping the top. :) IUGA leggings in this photo, too. Writing a review on those too. @shopgirlz.50something