Ideally, your dining room rug should be about four feet longer and wider than your table. You need 18 to 24 inches on each side so you and your guest can slide chairs out without worrying about falling off the edge of the rug. If your rug is too small, the chair can still scratch the floor, get tangled in the edge of the rug, and cause discomfort, embarrassment, and frustration when trying to slide the chair back in place.
To determine the size of the rug you need, first, measure your table. Then add 36 to 48 inches to each measurement. Be sure to include any table extension leaves into your measurement to accommodate the entire length of your table. In most cases, an 8x10 or 9x12 rug will fit your area and leave plenty of room for your chairs.