Read a few interior design blogs and you'll notice there are a lot of "rules" to follow when decorating your home. These rules, however, mostly serve as guidelines and are created not to limit you, but to help. Many times the rules have exceptions, or you at least have different options to choose from. Living room area rugs, for example, can be arranged in several ways depending on your space's setup and the area rug's size.
The rule for arranging your area rug is to have furniture placed on the rug. But what does this mean? Should you have your sofa and chairs sitting entirely on the rug or just the front legs? That depends on how large your area rug is and what you are trying to accomplish. First, let's start with why this rule exists in the first place. Mainly, it has to do with rug size. A larger rug allows you to arrange furniture on top of it, not around it. A rug that's too small can make a tiny living room feel smaller, and it can make a large room seem lacking. Placing your furniture on top of the rug also prevents people from tripping on the fabric edges when walking around the room.
Now that you know why it's common to place furniture on the rug, let's discuss your options. You can have whole pieces of furniture placed on top of a rug, or you can just place a part of your sofa on it. If you have an open floor plan, setting all of your floating furniture on the rug helps anchor the space. Other than that, it's mostly a matter of preference. Try both options and decide what looks best in your space.
Are there situations where a living room looks best when only the coffee table is placed on the rug? Of course — there are always exceptions to the rule! If you currently own a smaller rug, go ahead and try this method. If the look doesn't feel right, however, you'll most likely need to invest in a larger rug to complete your setup.