Convert Circular Mil (circ mil) to Square Foot (ft²) 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 Foot (ft²)
A square foot is the area of a square one foot on each side. It is widely used in the United States, the UK (historically), Canada (in real estate), and other regions where imperial units remain culturally influential. Square feet dominate property listings, architectural blueprints, and interior design specifications in the US. The measurement provides an intuitive scale for rooms and buildings, fitting well with common human-scaled dimensions. Although metrication has reduced its use worldwide, the square foot remains deeply embedded in construction codes, real estate markets, and consumer expectations in countries that continue to rely on imperial or hybrid systems. Its survival highlights the cultural persistence of traditional measurement systems despite global standardization.