Millimeters to Mils Conversion

FAQs

How many mils are there in one millimeter?

One millimeter equals exactly 39.3701 mils. A mil is a thousandth of an inch (0.001 in), commonly used in engineering, manufacturing, and printing to measure very small thicknesses.

How small is a mil compared to a millimeter?

A mil is very small - approximately 0.0254 mm. That means a single millimeter contains about 39 mils.

What is the relationship between millimeters, inches, and mils?

The relationship is based on the inch: 1 inch = 25.4 mm = 1,000 mils. Therefore, 1 mm = 39.3701 mils. This allows engineers and technicians to switch easily between metric and imperial measurements when working on precision components.

When should I use mils instead of millimeters?

Use mils for very fine measurements in electronics, coatings, film thickness, and PCB design. Millimeters are more practical for larger components, mechanical parts, and everyday length measurements. Mils provide higher resolution for thin materials, making them indispensable in micro-engineering applications.