Convert Thou to Millimeters
Convert Thou (th) to Millimeters (mm) instantly and accurately.
Conversion Formula
mm = th × 0.0254
About Thou
A thou (also called mil) is one thousandth of an inch, equal to 0.0254 millimeters or 25.4 micrometers. This unit is commonly used in engineering and manufacturing in countries that use imperial measurements, particularly for specifying tolerances, wire gauges, and thin material thicknesses. For example, a standard plastic bag might be 1-2 thou thick, a sheet of paper is about 4 thou, and precision machined parts often have tolerances measured in thou. Electronic circuit board copper traces are typically 1.4 thou thick.
About Millimeters
A millimeter (mm) is one thousandth of a meter, making it the smallest unit commonly used in everyday measurements. To visualize this, a credit card is about 1 mm thick, and a paperclip wire is roughly 1 mm in diameter. Millimeters are essential in engineering, manufacturing, and medicine for precise measurements. Rainfall is measured in millimeters, with 1 mm representing a very light drizzle. Most rulers and measuring tapes include millimeter markings for accuracy.
Quick Reference Table
| Thou (th) | Millimeters (mm) |
|---|---|
| 1 th | 0.0254 mm |
| 2 th | 0.0508 mm |
| 5 th | 0.127 mm |
| 10 th | 0.254 mm |
| 25 th | 0.635 mm |
| 50 th | 1.27 mm |
| 100 th | 2.54 mm |