Shape of the Room
Most rooms are either square or rectangular, but there are many exceptions. By choosing the right shape of rug, you can enhance the size and shape or correct oddly proportioned rooms.
If your room has odd angles, a round rug can unify the space and add a little whimsy, where a rectangular rug might seem at odds with the room shape. For very large living spaces, rectangular rugs can be used to define a conversation area. Simply place your sofa, chairs and coffee table on the rug. A rectangular rug is usually the best choice as a door mat; however, a small round rug works well in a kitchen or bathroom, where users cross in many directions.
Rectangular rugs are, without a doubt, the most common shape of rug. Therefore, they come in many different sizes, which are standardized. Most rugs are called out, for example, "8 by 10," which refers to the width and the length and follows the British Imperial System. You can purchase rectangular rugs from as small as 2 by 3 feet as a door mat, up to 14 by 21 feet for a large living space. Round rugs are less common than rectangular rugs, but they are also defined by their length and width, which, of course, will always be the same. Typical sizes include 4 by 4, which has a 4-foot diameter, and 8 by 8, which has an 8-foot diameter. Before purchasing a rug of either shape, measure your space and be sure you leave enough of the floor exposed around the rug so that it doesn't take over the room. Also consider traffic patterns and furniture placement.
Rectangular and round rugs aren't the only options. You may decide that a square or oval-shaped rug, or a hexagonal rug, better fits your space. These rug shapes can be good choices for historic homes, which often feature rooms with interesting geometric shapes. A square rug, for example, is ideal for use in a square room, just as a hexagonal or octagonal rug can accentuate a room of the same shape. An oval rug provides a softer effect than the hard edges of a rectangular rug. Keep in mind, however, that these rug shapes aren't common and therefore aren't available in a wide range of sizes.