Micrometer to Millimeter Converter

Length Converter

31 units available

Decimals:

From

To

0.001

1 µm = 0.001 mm

Formula:

mm = µm × 0.001

With your value: 1 µm = 0.001 mm

How big is that?

Everyday references on a logarithmic scale, all expressed in micrometer so you can sanity-check the result.

Your value1.00 µm

Grain of sand (5.0e+2× your value)500 µm

Credit card (long side) (8.6e+4× your value)8.56e+4 µm

A4 sheet (height) (3.0e+5× your value)2.97e+5 µm

Adult stride (7.5e+5× your value)7.50e+5 µm

Standard door height (2.0e+6× your value)2.00e+6 µm

Other Micrometer to Millimeter conversions

2 µm to mm 3 µm to mm 4 µm to mm 5 µm to mm 6 µm to mm 7 µm to mm 8 µm to mm

Micrometer to Millimeter Conversion Table

Micrometer (µm)	Millimeter (mm)
0.5	0.0005
1	0.001
2	0.002
5	0.005
10	0.01
15	0.015
20	0.02
25	0.025
50	0.05
100	0.1
250	0.25
500	0.5
1000	1

Millimeter to Micrometer Conversion Table

Millimeter (mm)	Micrometer (µm)
0.5	500
1	1,000
2	2,000
5	5,000
10	10,000
15	15,000
20	20,000
25	25,000
50	50,000
100	100,000
250	250,000
500	500,000
1000	1,000,000

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Micrometer (µm)

Length

Exact conversion

Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

Millimeter (mm)

Length

Exact conversion

Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

How to Convert Micrometer to Millimeter

To convert from Micrometer (µm) to Millimeter (mm), multiply the value by 0.001.

Formula: mm = µm × 0.001

Reverse: µm = mm × 1,000

Step-by-Step Example

Start with your value in Micrometer. For example: 5 µm
Multiply by the conversion factor: 5 x 0.001
The result is: 0.005 mm

About Micrometer

The micrometre (micron) equals one millionth of a metre. It is the working scale of cells, machining tolerances and airborne particulates.

Common uses: microscopy, machining tolerances, air quality (PM).

About Millimeter

The millimeter equals one thousandth of a meter and is used for precise measurements in engineering and manufacturing.

Common uses: engineering, rainfall measurement, manufacturing.

Frequently Asked Questions

How many Millimeter are in 1 Micrometer?

There are exactly 0.001 Millimeter in 1 Micrometer. This means the conversion factor from Micrometer to Millimeter is 0.001.

What is the formula to convert Micrometer to Millimeter?

The formula to convert Micrometer to Millimeter is: mm = µm × 0.001. For example, to convert 10 Micrometer to Millimeter, you would multiply 10 by 0.001.

What is a Micrometer?