Thou (Mils) to Micrometers (th → µm)
Formula
1 th = 25.400000000000002 µmConversion Table
| th | µm |
|---|---|
| 0 | 0 |
| 1.0000 | 25.400 |
| 2.0000 | 50.800 |
| 3.0000 | 76.200 |
| 4.0000 | 101.60 |
| 5.0000 | 127.00 |
| 6.0000 | 152.40 |
| 7.0000 | 177.80 |
| 8.0000 | 203.20 |
| 9.0000 | 228.60 |
| 10.000 | 254.00 |
| 11.000 | 279.40 |
| 12.000 | 304.80 |
| 13.000 | 330.20 |
| 14.000 | 355.60 |
| 15.000 | 381.00 |
| 16.000 | 406.40 |
| 17.000 | 431.80 |
| 18.000 | 457.20 |
| 19.000 | 482.60 |
| th | µm |
|---|---|
| 20.000 | 508.00 |
| 21.000 | 533.40 |
| 22.000 | 558.80 |
| 23.000 | 584.20 |
| 24.000 | 609.60 |
| 25.000 | 635.00 |
| 26.000 | 660.40 |
| 27.000 | 685.80 |
| 28.000 | 711.20 |
| 29.000 | 736.60 |
| 30.000 | 762.00 |
| 31.000 | 787.40 |
| 32.000 | 812.80 |
| 33.000 | 838.20 |
| 34.000 | 863.60 |
| 35.000 | 889.00 |
| 36.000 | 914.40 |
| 37.000 | 939.80 |
| 38.000 | 965.20 |
| 39.000 | 990.60 |
| th | µm |
|---|---|
| 40.000 | 1,016.0 |
| 41.000 | 1,041.4 |
| 42.000 | 1,066.8 |
| 43.000 | 1,092.2 |
| 44.000 | 1,117.6 |
| 45.000 | 1,143.0 |
| 46.000 | 1,168.4 |
| 47.000 | 1,193.8 |
| 48.000 | 1,219.2 |
| 49.000 | 1,244.6 |
| 50.000 | 1,270.0 |
| 51.000 | 1,295.4 |
| 52.000 | 1,320.8 |
| 53.000 | 1,346.2 |
| 54.000 | 1,371.6 |
| 55.000 | 1,397.0 |
| 56.000 | 1,422.4 |
| 57.000 | 1,447.8 |
| 58.000 | 1,473.2 |
| 59.000 | 1,498.6 |
| th | µm |
|---|---|
| 60.000 | 1,524.0 |
| 61.000 | 1,549.4 |
| 62.000 | 1,574.8 |
| 63.000 | 1,600.2 |
| 64.000 | 1,625.6 |
| 65.000 | 1,651.0 |
| 66.000 | 1,676.4 |
| 67.000 | 1,701.8 |
| 68.000 | 1,727.2 |
| 69.000 | 1,752.6 |
| 70.000 | 1,778.0 |
| 71.000 | 1,803.4 |
| 72.000 | 1,828.8 |
| 73.000 | 1,854.2 |
| 74.000 | 1,879.6 |
| 75.000 | 1,905.0 |
| 76.000 | 1,930.4 |
| 77.000 | 1,955.8 |
| 78.000 | 1,981.2 |
| 79.000 | 2,006.6 |
Thou (Mils) to Micrometers Conversion
Converting Thou (Mils) (th) to Micrometers (µm) is a common length conversion. 1 th equals 25.4 µm. For example, 100 th is equal to 2,540 µm.
Quick Mental Math: Thou (Mils) to Micrometers
Reference a linear anchor between thou and micrometers; use one memorable value.
Why is converting Thou (Mils) to Micrometers tricky?
Magnitude or direction confusion between thou and micrometers is the primary error source.
Quick Reference Values
1 th = 25.4 µm. 5 th = 127 µm. 10 th = 254 µm. 25 th = 635 µm. 50 th = 1,270 µm. 100 th = 2,540 µm.
What is Thou (Mils)?
Thou (Mils) (th) is a unit of length. A thou is a unit of length equal to one thousandth of an inch (0.001 in). It corresponds to exactly 25.4 micrometers (µm) in SI units. The thou is widely used in engineering and manufacturing for precise measurements of thickness and diameter [nist-si-guide]. The thou emerged in the 19th century in British engineering as a convenient subdivision of the inch. Its use was formalized to provide accuracy in machining and toolmaking, reflecting industrial measurement needs [nist-si-guide]. The thou remains common in the United States, Canada, and the UK for mechanical engineering and machining tolerances. It is frequently used in the automotive and aerospace industries for component specifications [nist-si-guide].
What is Micrometers?
Micrometers (µm) is a unit of length. A micrometer, symbolized as µm, equals one millionth of a meter or 10⁻⁶ meters. It is the SI derived unit for length used to measure microscopic distances and thicknesses. This precise definition aligns with the International System of Units established by the BIPM [bipm-si-brochure]. The micrometer was standardized in the 20th century following adoption of the meter as the base unit by the CGPM. Its use became widespread in scientific fields requiring fine measurement, formalized in SI documentation [cgpm-resolutions]. The micrometer sees global use in sectors like semiconductor manufacturing, biology, and materials science. Countries with advanced manufacturing industries such as Japan, Germany, and the USA standardize on µm for precise length measurements [nist-si-guide].
Common Misspellings
People often search for this conversion using these alternate spellings: thow, thouh, thous, micronmeter, micrometeres, micomenter, micrmeters. All of these refer to the Thou (Mils) to Micrometers conversion.