Honesty time: I'm 5'4" and 155 lbs, with my weight fairly evenly distributed and the medium fits very well. If you're looking for a fitted look, order one size down but the shoulder area will be a little tight. Personally, I really dislike plaid flannel shirts as a fashion item but after a recent trip to Seattle and with an upcoming trip to Denver, I decided to get one for traveling out west. The Jazzy/Coral Reef/Petunia/Aqua Glow color is fantastic. I love the colors and the size of the plaid. In fact, I liked it so much I ordered two more, one in Southern Fall/Opaque White Plaid (not bad, not as nice as the picture) and Canyon Maple/Blue Violet Plaid (not pretty at all, it'll be returned). If you're new to plaid like me, I highly recommend the larger print as a way to ease into this style. The quality is good. The shirt is not very fitted but it's not meant to be. I plan on wearing it open with a tank top or with a sweater over it. Good quality.