Convert Square Millimeters to Square Thou
Convert Square Millimeters (mm²) to Square Thou (thou²) instantly and accurately.
Conversion Formula
thou² = mm² × 1550.0031
About Square Millimeters
A square millimeter (mm²) is a metric unit of area equal to a square with sides of one millimeter. It is commonly used in precision engineering, electronics, and measuring very small surfaces such as microchips or printed circuit boards. To visualise: a typical pinhead has an area of about 2-3 mm². This unit is essential in microscopy, medical imaging, and manufacturing where tiny, precise measurements are critical.
About Square Thou
A square thou (thou²), sometimes called a square mil, is the area of a square with sides of one thousandth of an inch (0.0254 mm), equal to approximately 6.452 × 10⁻¹⁰ m². This tiny imperial unit is indispensable in precision engineering, PCB (printed circuit board) design, and manufacturing, where conductor widths, dielectric coating thicknesses, and tight machining tolerances are specified in thou. Wire insulation, thin films, and precision-stamped metal components are commonly described using this unit.
Quick Reference Table
| Square Millimeters (mm²) | Square Thou (thou²) |
|---|---|
| 1 mm² | 1550 thou² |
| 2 mm² | 3100.01 thou² |
| 5 mm² | 7750.02 thou² |
| 10 mm² | 15500 thou² |
| 25 mm² | 38750.1 thou² |
| 50 mm² | 77500.2 thou² |
| 100 mm² | 155000 thou² |