Square Millimeters Converter

Convert square millimeters (mm²) to square centimeters, meters, inches, and other area units.

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The square millimeter (mm²) is a metric unit of area equal to the area of a square with sides of one millimeter. Used in engineering, microelectronics, medicine, and print, where high precision is required.

Common Square Millimeter Conversions

  • 1 mm² = 0.01 cm² — one hundred square millimeters equal one square centimeter.
  • 1 mm² = 0.000001 m² — one million square millimeters equal one square meter.
  • 1 mm² ≈ 0.00155 in² — multiply by 0.00155 to get square inches.
  • 645.16 mm² = 1 in² — exact value by definition.

Square millimeters are the standard in technical documentation and engineering drawings. They are also used to denote the cross-sectional area of wires and cables in electrical engineering.