mil to millimeter Converter
Convert mil to mm and back with a live reference table.
1 mil = 0.0254 mm\n5 mil = 0.127 mm\n10 mil = 0.254 mm\n25 mil = 0.635 mm\n50 mil = 1.27 mm\n100 mil = 2.54 mm
Why this conversion matters
Mil thickness often appears on packaging and tape specs, while metric drawings usually need the same value in millimeters. The widget keeps the direction explicit so you can enter either side of the pair without doing the reciprocal by hand. It is built for quick checks where a calculator, specification sheet, recipe, map, or lab note uses the other unit.
For the default example, 10 mil converts to 0.254 mm. Switching the direction shows the inverse relationship, so 0.254 mm converts back to 10 mil with the same factor.
Formula and privacy note
The calculation uses 1 mil = 0.0254 mm. Forward conversion multiplies by that factor, and reverse conversion divides by it. Results are rounded to six significant figures for readable estimates, so very small scientific units and large planning units stay scannable. Check the unit labels before copying a result, especially when similar abbreviations appear in the same project. The reference table is generated from the same constant, and everything runs locally in your browser.
Frequently Asked Questions
What factor does this converter use?
It uses the standard factor 1 mil = 0.0254 mm, then applies the reciprocal for the reverse direction.
Why are results rounded?
The main result is rounded to six significant figures so very large and very small values stay readable while preserving the useful precision for quick checks.
Can I convert both directions?
Yes. Choose mil to mm or mm to mil from the direction menu and the output updates immediately.
Is this converter private?
Yes. The conversion runs entirely in your browser, and the value you enter is not uploaded or stored.
Browse the full set of free, private, in-browser tools.