There was no reviews to go off of, so I sized up two sizes because the product details said moderate stretch and from experience, most sets like this I have to size up because I’m thick in the breast and but area. My normal size is a medium but I ordered XL just to be safe. Shouldn’t have done that. Lol! I will be sending back and ordering a medium because this set is so cute I have to have it. Stick with your normal size because the pants are on the baggy fit size so you will have a little room. Can’t wait to see how the medium fits!