What is the ideal size for a dining room rug?

The most general rule of thumb when placing a rug under your dining room table is that the table and chairs should be sitting on the rug, even when the chairs are pulled out. You can use the dining room table as a base to measure your rug, though it's often advisable to err on the side of a bigger rug. Another great design idea is to have your rug match the shape of your table, whether round, rectangle or oval.