Micrometers to Millimeters Converter

Enter the length in micrometers below to get the value converted to millimeters.


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Result in Millimeters:

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1 µm = 0.001 mm

Do you want to convert millimeters to micrometers?

How to Convert Micrometers to Millimeters

To convert a measurement in micrometers to a measurement in millimeters, divide the length by the following conversion ratio: 1,000 micrometers/millimeter.

Since one millimeter is equal to 1,000 micrometers, you can use this simple formula to convert:

millimeters = micrometers ÷ 1,000

The length in millimeters is equal to the length in micrometers divided by 1,000.

For example, here's how to convert 5,000 micrometers to millimeters using the formula above.
millimeters = (5,000 µm ÷ 1,000) = 5 mm
conversion scale showing micrometers and equivalent millimeters length values

Our inch fraction calculator can add micrometers and millimeters together, and it also automatically converts the results to US customary, imperial, and SI metric values.

Micrometers and millimeters are both units used to measure length. Keep reading to learn more about each unit of measure.

What Is a Micrometer?

One micrometer is equal to one-millionth (1/1,000,000) of a meter, which is defined as the distance light travels in a vacuum in a 1/299,792,458 second time interval.

The micrometer, or micrometre, is a multiple of the meter, which is the SI base unit for length. In the metric system, "micro" is the prefix for millionths, or 10-6. A micrometer is sometimes also referred to as a micron. Micrometers can be abbreviated as µm; for example, 1 micrometer can be written as 1 µm.

To get an idea of the actual physical length of a micrometer, one human hair is 40-50 µm thick, demonstrating how small this unit of measure is.

Learn more about micrometers.

What Is a Millimeter?

One millimeter is equal to one-thousandth (1/1,000) of a meter, which is defined as the distance light travels in a vacuum in 1/299,792,458 of a second. One millimeter is equal to 0.0393701 inches.

The millimeter, or millimetre, is a multiple of the meter, which is the SI base unit for length. In the metric system, "milli" is the prefix for thousandths, or 10-3. Millimeters can be abbreviated as mm; for example, 1 millimeter can be written as 1 mm.

Millimeters are often represented by the smallest ticks on most metric rulers. To get a reference point of the size, the thickness of a US dime is 1.35mm.[1]

Learn more about millimeters.

We recommend using a ruler or tape measure for measuring length, which can be found at a local retailer or home center. Rulers are available in imperial, metric, or a combination of both values, so make sure you get the correct type for your needs.

Need a ruler? Try our free downloadable and printable rulers, which include both imperial and metric measurements.

Micrometer to Millimeter Conversion Table

Table showing various micrometer measurements converted to millimeters.
Micrometers Millimeters
1 µm 0.001 mm
2 µm 0.002 mm
3 µm 0.003 mm
4 µm 0.004 mm
5 µm 0.005 mm
6 µm 0.006 mm
7 µm 0.007 mm
8 µm 0.008 mm
9 µm 0.009 mm
10 µm 0.01 mm
20 µm 0.02 mm
30 µm 0.03 mm
40 µm 0.04 mm
50 µm 0.05 mm
60 µm 0.06 mm
70 µm 0.07 mm
80 µm 0.08 mm
90 µm 0.09 mm
100 µm 0.1 mm
200 µm 0.2 mm
300 µm 0.3 mm
400 µm 0.4 mm
500 µm 0.5 mm
600 µm 0.6 mm
700 µm 0.7 mm
800 µm 0.8 mm
900 µm 0.9 mm
1,000 µm 1 mm


  1. United States Mint, Coin Specifications, https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications

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