According to the Ex Officio size chart, I am absolutely a large. Unfortunately, it wasn't until after I'd washed this that I discovered it fit way too loose for a shelf bra. But the fabric is very cool and soft, so I ordered a medium and that's probably the best fit I'll find with this item. Still, I could never wear just this camisole under a blouse: there's nowhere near enough support (even though I'm not buxom) and nipple contours show right through. Find it odd that there's a seam in middle of lace in front; not the most attractive for peeking out. That said, this cami is perfect for wearing around the house, where comfort is most important, and at this price (about $19 for my style, the lowest I've seen anywhere) I can afford to have two for just that purpose.