When you see rugs hanging in a showroom, keep in mind that they look a lot bigger than when they are on the floor. Therefore, it can be tricky to guess the rug size you need just by looking at a room or a rug. You need to actually measure the size of the space, and know how much of the floor you want covered, as well as know which pieces of furniture you want placed on the area rug. These illustrations should help you decide:
For larger living rooms you can float furniture in the center of the room. It’s important that the furniture doesn’t feel squished on the rug, so make sure there is breathing room around all the edges.
For medium-sized living rooms you can place the furniture against the walls, putting a rug in the center with the front legs of the furniture on the rug and the back legs on the floor.
For smaller, more compact living rooms you can place a rug in front of the furniture, filling the space created in the middle by the furniture. Here it shows putting the coffee table on the rug.