Convert Circular Mil (circ mil) to Square Mile (mi²) 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 Mile (mi²)
A square mile equals 640 acres or about 2.58999 km². It is the primary unit for describing large areas in the United States and the UK, particularly in geography and land-use planning. City sizes, county boundaries, national park dimensions, and lake surfaces are often expressed in square miles. Because of its large scale, it is ideal for measuring political subdivisions, conservation zones, and territorial claims. The square mile also appears in demographic statistics—such as population density—and in historical surveys of American frontiers, where square-mile sections formed the backbone of land distribution policies.