Shift Items Regularly. Move heavy items, such as sofas and tables, a couple of inches every month or two to help prevent extreme carpet wear beneath the furniture legs. The longer the furniture sits in one place, the more it settles into the carpet. Protect a carpet from heavy furniture by using special coasters beneath the furniture legs. They can also be used as a way to define the space in your living room. The size of the area rug should depend on the size of the couch. If you have a small couch, then you should go for a smaller area rug. If you have a large sofa, then you should go for an area rug that is at least 3 feet by 5 feet in size. Gray rugs like Kashan 10x13 are an admirable way to complete the appearance of a gray sofa, and they can help to secure the furniture in the room. Gray rugs come in an array of shades, from light gray to charcoal, or gray-black rug 9x12; accordingly, you can easily find one that goes well with your sofa. 5. Neutral rugs. 3fqME.