The size runs a little small. I'm a 34A and usually a "small" but you'd need to be a size up and get a "medium" in this bra. It's extremely comfortable, there's a bit of padding in it (similar to the  padding in swim suits) for those who are self-conscious and it offers great support. This bra makes running a lot easier -- I'm not bouncing around. Just get a size up and it'll be well worth the purchase.