Make sure that all dining chairs sit comfortably on the rug and that the rug extends 36 inches beyond all sides of the dining table, but no less than 24 inches. When choosing a dining room rug, simply add a minimum of 60 inches to the length and the width of your table to get your ideal rug size.
Some may tell you to fit your living room rug just under the coffee table, and leave all seating off the rug. But interior designers name this decor faux pas as the number one decorating mistake seen in homes, and warn that small rugs can make a space look even smaller. If you feel you must go with a smaller rug, ensure that the front legs of all furniture pieces are able to sit on the rug. Ideally, it is best to have all furniture legs, including the sofas and accent chairs, sitting on the rug.Proper scale for a living room rug requires that the rug extend away from the furniture at least six inches on each side.To accomplish this, the preferred size would be a 9x12 foot rug or larger.
In the bedroom, you have a choice of three different design rules, including the two-thirds of the bed on the rug rule, and the runners on each side of the bed rule. Either of these is a good choice if your room is exceptionally large or asymmetrically shaped. Look for runners that won't extend beyond the bed itself but that are slightly wider than the nightstands.
To make small room look larger, you can choose to place all legs of the bed and surrounding furniture, including nightstands and foot bench, on the rug. With this choice, leave 18 to 24 inches of rug space around the edges of the furniture. Typically a king bed requires a 9 x 12 rug, a queen requires an 8 x 10 rug, and a full or twin should sit over a 6 x 9 or larger.
When the rug makes the room
Allow the room to dictate the size of your rug. Good interior design suggests that a rug should extend at least 6 to 12 inches, or even better, 12 to 18 inches beyond the furniture it's underneath. There is also the suggestion to leave approximately 18 to 24 inches between the perimeter of the rug and the walls.