Standard size The hexagonal height of a normal hexagonal "#2 pencil" is 1/4-inch (6 mm), although the outer diameter is somewhat bigger approximately 9/32-inch (7 mm). A normal # 2 hexagonal pencil is 19 cm (7.5 in) in length. There are other sizes of pencils available, including quadrangular pencils and mechanical pencils. Hexagonal pencils are commonly used by artists because they are easy to hold while creating drawings or paintings. They come in various sizes and shapes. The largest size available on the market is the # 4 pencil, which has a diameter of 5/8 inch (16 mm). The standard pencil size is most often used by architects when creating drawings for houses. These drawings usually include sections showing different parts of the house, such as walls, floors, and roofs. The section drawings should be proportionate to the size of the house so that how much material it takes to build it is not underestimated. For example, if the house is 20 feet long and 10 feet wide, then the section drawing for one floor should be about 3 by 5 feet. In addition to architects, engineers also use standard pencil sizes. When designing buildings, they first draw rough plans showing major components such as walls, floors, and roofs. Then they refine these initial designs with more detailed drawings prepared using standard pencil sizes.