Convert Section (section) to Circular Mil (circ mil) instantly.
About these units
Section (section)
A section is a unit of area equal to one square mile, or 640 acres, derived from the PLSS township system. Each township contains 36 sections arranged in a 6-by-6 grid. Sections were historically granted to settlers, railroads, and states for development, education funding, and agricultural expansion. Because a section is large but manageable, it provided a logical unit for dividing land among homesteaders. Even today, the section persists as a foundation of rural property boundaries. Many farms, ranches, and municipal boundaries reference section lines, reflecting how 19th-century surveying still shapes 21st-century land use.
Circular Mil (circ mil)
A circular mil is defined as the area of a circle with a diameter of exactly one mil. Because wires and cables have circular cross-sections, the circular mil has become a standard unit in electrical engineering for specifying conductor sizes. One circular mil simplifies calculations because area scales directly with the square of wire diameter without needing π in computations. For example, doubling a wire's diameter increases its circular-mil area fourfold. This makes circular mils extremely convenient for determining ampacity, resistance, and voltage drop in electrical conductors. Even though SI units are common elsewhere, the circular mil remains entrenched in North American electrical codes.