Convert Circular Mil (circ mil) to Square Rod (rod²) instantly.
About these units
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.
Square Rod (rod²)
A square rod, also known as a perch or pole in some traditions, equals the area of a square one rod on each side (1 rod = 16.5 feet). This results in 272.25 square feet. Square rods were widely used in medieval English farming and early American surveying to measure garden plots, small fields, and building sites. Because land taxes were often assessed per rod, the unit became a practical economic tool as well. Though no longer widely used, the square rod appears in historical deeds and archival surveys, making it critical for land historians and legal property research.