Convert Circular Inch (circ in) to Square Inch (in²) instantly.
About these units
Circular Inch (circ in)
A circular inch represents the area of a circle with a diameter of exactly one inch. This yields an area of approximately 0.7854 square inches. It is sometimes used in engineering, especially in the sizing of pipes, hydraulic fittings, and certain mechanical components where circular cross-sections dominate. While not as widespread as the square inch, the circular inch offers a more direct representation of the actual shape of round components, reducing the need for manual geometric conversion.
Square Inch (in²)
A square inch represents the area of a one-inch by one-inch square. It is indispensable in engineering, manufacturing, machine design, and consumer product specifications. Mechanical components, gasket areas, electronic device screens, and pipe cross-sections are often measured in square inches. Because imperial units are deeply rooted in American manufacturing, the square inch enables precise communication among engineers and technicians. The unit remains important in pressure measurement as well—psi (pounds per square inch) combines force and area into one of the most widely recognized engineering units worldwide.