I am a 42DD and I ordered a 44DD because some reviews were saying that the bra runs a size small. I got the product 1 day earlier than exspected so that was nice. i was sure that a cup size up would fit, but when i recieved the product and tried it on it was very tight. I noticed when i put the bra on the last hook then it fits a little better, but it's still a very snug fit. Not sure yet if i wanna send it back or keep it? the support is great and very little movement. Maybe it needs to be so snug to hold eveything in. kinda like a spanx lol. overall i really like the product. i would just go a size up if your purchasing DD size.