I am 5'8", 140lbs, fairly fit, usually a size 8 in tops and dresses. I got the medium to make sure it wasn't too baggy around my upper body. It is not tight around my armpits! After washing warm, the sleeves are a few inches above my wrists, and the hem hits just above mid calf. I'm so happy with this nightgown. I can wear it out of my room to make breakfast for kids and kid guests without any see-through issues. I got it in Black, and want to get another in a lighter color. Fabric is perfect - thick enough, but not too warm. No static and doesn't cling to my sheets. I highly recommend this product!