I absolutely LOOOVE my white sherpa pullover! I'm 5'5" and 150 lbs, I purchased the Medium, which is perfectly roomy. I can comfortably wear a t-shirt underneath. I probably could've ordered a size Small if I wanted a tighter fit. I also like the grey undertone to the white so that the pullover isn't just... white. This is absolutely my new favorite staple in my winter wardrobe.