Mil
The mil, or thou, is one thousandth of an inch: exactly 25.4 µm. It is not a millimetre.
Symbol: mil
Quantity: length and distance
SI relation: 1 mil = 0.0000254 m (exact)
Derivation: 1 mil = 0.001 in = 25.4 µm (exact)
Exact: yes, by definition
Typical uses
- Plastic film and bag thickness
- Coating and paint film thickness
- PCB copper and trace dimensions
Convert mils to other units
| Conversion | 1 mil equals | Reverse |
|---|---|---|
| mil to meter | 0.0000254 m | meter to mil |
| mil to kilometer | 2.54 × 10⁻⁸ km | kilometer to mil |
| mil to centimeter | 0.00254 cm | centimeter to mil |
| mil to millimeter | 0.0254 mm | millimeter to mil |
| mil to mile | 1.578282828 × 10⁻⁸ mi | mile to mil |
| mil to foot | 0.00008333333333 ft | foot to mil |
| mil to inch | 0.001 in | inch to mil |
| mil to micrometer | 25.4 µm | micrometer to mil |
| mil to nanometer | 25400 nm | nanometer to mil |
| mil to yard | 0.00002777777778 yd | yard to mil |
| mil to nautical mile | 1.371490281 × 10⁻⁸ nmi | nautical mile to mil |
| mil to angstrom | 254000 Å | angstrom to mil |
Open the Length Converter to convert any value between all units.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "mil (0.001 in)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Mil. Retrieved October 17, 2026, from https://scientificconverters.com/units/mil/
IEEE
Scientific Converters, "Mil," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/mil/