Convert Square Foot (US Survey) (ft² (US)) to Square Inch (in²) instantly.
About these units
Square Foot (US Survey) (ft² (US))
The US survey square foot is defined using the US survey foot and differs minutely from the international square foot. While the difference is negligible in everyday contexts, in land surveying even tiny discrepancies matter because property boundaries, right-of-way extents, and engineering alignments may accumulate errors over long distances. Surveyors and civil engineers must interpret historical documents using survey-based values to ensure legal consistency with old plats, deeds, and boundary descriptions.
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.