Convert Circular Mil (circ mil) to Square Micrometer (µm²) 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 Micrometer (µm²)
A square micrometer, also called a square micron, equals 10⁻¹² square meters. It is a fundamental unit in microbiology, nanotechnology, semiconductor physics, and materials characterization. Cells, organelles, thin films, and laser spot sizes are frequently measured in µm². In semiconductor fabrication, transistor gates, nanoscale features, and photolithographic patterns often have areas measured at this scale. At such dimensions, quantum effects, crystal lattice structures, and electron mobility become important, making µm² not just a geometric unit but a bridge to fundamental physical behavior at microscopic scales.