When shopping for a Persian rug for a dining room, there are several factors to consider. First, consider the size of the room and the size of your dining table. Next, you'll want to choose a large enough rug to fit comfortably under the table and chairs, with enough room for guests to pull their chairs in and out without catching on the carpet. A good rule of thumb is to choose a rug at least two feet wider and longer than your dining table.