I'm small chested,  normally a 36B. That's the size I ordered, even though many reviews say to go up a size. It fit me just fine. I didn't get any push-up action, but I really didn't expect it based on the style of the bra. It provides the coverage I want without being visible under a low cut shirt.  So far, I've only worn it for a few minutes to try it on. It stayed in place and was comfortable. Not sure what it will be like with extended periods of time. But, I'm sure it will be fine. No complaints about the product.