Mils to millimeters Converter

This page allows you to convert length values expressed in mils to their equivalent in millimeters.

Enter the value in mils in the top field (the one marked "mil"), then press the "Convert" button or the "Enter" key. The converter also works the other way round: if you enter the value in millimeters in the "mm" field, the equivalent value in mils is calculated and displayed in the top field.

Mils to Millimeters Conversion Formula

$L_{millimeters}=L_{mils} * \frac{127}{5000}$

Where Lmils is the length in mils and Lmillimeters is its equivalent in millimeters.

Reverse formula (millimeters to mils)


The mil is a unit of measure typically used in manufacturing and engineering for describing distance tolerances with high precision or for specifying the thickness of materials. One mil is equal to one thousandth of an inch, or 10-3 inches.

The mil is also referred to as thou.

The closest unit to the mil in the metric system is the micrometer: One mil is equal to 25.4 Ám.


One millimeter, in the metric system, is equivalent to 1/1000 (one thousandth) of a meter. 1 mm = 10-3 m.

It is used to describe lengths that are relatively small, like the widths of pipes, cables or connectors. The well known terms 8mm, 16mm and 32mm describe common widths of motion picture films.

To understand the approximate size of one millimeter, see this tiny red line: 1mm line.    And this line should be approximately five millimeters long: 5mm line