39 and 41.5

this is a loose fitting, not tight fitting shirt. It is generously cut, so a woman with a larger bust could still feel modest wearing this. A large petite would be slightly shorter, but since the shirt falls just below the hips, a petite might be long enough, unless if you are very tall or very large in the bust area. A medium would look good on someone who is petite, as I would rather have something a bit loose, considering the casual style, than choosing a smaller size and having it feel tight across the chest. If you don't have access to a JJill store in your area and are uncertain about the best size for you, customer service is very helpful and knowledgeable.good luck! I hope you can find the right size. I personally love the ease and casual style of these shirts and have bought several over the years.