String (str) is a unit of length equal to 12 feet, 144 inches, 4 yards, 3.6576 meters, or 0.72 rods. The term is originated from that that the common length of strings sold is 144 feet long. This unit can be used in alternate to yards or meters, e.g. the house next door is about two strings away. It is also called the room length since it is the length of one side of the room when formed in square.