Convert Square Millimeter (mm²) to Square Mile (US Survey) (mi² (US)) instantly.
About these units
Square Millimeter (mm²)
A square millimeter represents the area of a square measuring 1 millimeter on each side. It is a tiny unit used extensively in engineering, electronics, material science, and medical instrumentation. Mechanical designers use mm² to determine cross-sectional areas of wires, beams, micro-mechanical parts, and precision components. In electronics, PCB traces, microchips, and sensors often specify dimensions in mm² for clarity and precision. Biomedical sciences also use mm² for cell colony measurements, tissue sample surfaces, and microscopic fields of view. Its size makes it ideal for quantifying structures too small for cm² but too large for micrometer-scale units.
Square Mile (US Survey) (mi² (US))
The US survey square mile is extremely close to the international square mile but is defined using the US survey foot, a slightly different value than the international foot historically used in land surveying. This unit appears in American land deeds, cadastral maps, and federal land management documents. The Public Land Survey System (PLSS), which divided much of the western United States into townships and sections, relied heavily on survey-based square miles. Although the modern US has transitioned to the international foot (as of 2023), historical land descriptions remain legally tied to the survey-based definition, ensuring its continued relevance.