Mils to Millimeters
Convert mils to millimeters instantly. 1 mil = 0.0254 mm. Includes the exact factor, a conversion table of common values and the definition of both units.
How to convert mils to millimeters
To convert mils to millimeters, divide by 39.3700787402 (multiply by 0.0254). The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.
mm = mil × 0.0254
Mils to Millimeters conversion table
The values people look up most often, rounded for reading. Use the calculator above for anything in between.
| Mils | Millimeters |
|---|---|
| 1 mil | 0.0254 mm |
| 2 mil | 0.0508 mm |
| 3 mil | 0.0762 mm |
| 5 mil | 0.127 mm |
| 10 mil | 0.254 mm |
| 20 mil | 0.508 mm |
| 25 mil | 0.635 mm |
| 50 mil | 1.27 mm |
| 100 mil | 2.54 mm |
| 500 mil | 12.7 mm |
| 1,000 mil | 25.4 mm |
What is a mil?
One thousandth of an inch. Standard for PCB traces, foil and coating thickness.
What is a millimeter?
A thousandth of a metre. The default fine unit on metric engineering drawings.
The formula
mm = mil × 0.0254
Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.
How to use the Mils to Millimeters
- Type the number of mils you want to convert.
- Read the result in millimeters straight away — there is no button to press.
- Check the table below for the values that come up most often, or reverse the conversion with the linked millimeters to mils page.
Mils to Millimeters — frequently asked questions
How many millimeters are in a mil?
One mil equals 0.0254 mm. mm = mil × 0.0254
What is the formula to convert mils to millimeters?
The formula is mm = mil × 0.0254. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.
How do I convert millimeters back to mils?
Divide instead of multiplying: one millimeter is 39.3700787402 mil. The reverse converter is linked in the related tools list.
Is this conversion exact?
Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.
Is this mils to millimeters free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
What people search for
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About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 15, 2026 · Calculation runs client-side · No data collected · Report an error