Convert Square Foot (US Survey) (ft² (US)) to Square Mil (mil²) 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 Surveyors and civil engineers must interpret historical documents using survey-based values to ensure legal consistency with old plats, deeds, and boundary descriptions.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 Mil (mil²)
A square mil equals the area of a square one mil (0.001 inch) on each side, producing an area of one-millionth of a square inch. This tiny unit appears in microfabrication, thin-film manufacturing, and fine electronic component design. Engineers rely on mils and mil² for PCB trace design, wire bonding pads, and micro-mechanical parts. Despite modern efforts to shift toward metric units, mils remain deeply embedded in American electronics manufacturing due to legacy tooling and engineering standards.