Millimeter to Micrometer Converter

Length Converter

31 units available

Decimals:

From

To

1,000

1 mm = 1,000 µm

Formula:

µm = mm × 1,000

With your value: 1 mm = 1,000 µm

How big is that?

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

Grain of sand (1/2.0 your value)0.500 mm

Your value1.00 mm

Credit card (long side) (86× your value)85.6 mm

A4 sheet (height) (3.0e+2× your value)297 mm

Adult stride (7.5e+2× your value)750 mm

Standard door height (2.0e+3× your value)2.00e+3 mm

Other Millimeter to Micrometer conversions

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

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

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

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.

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

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

How to Convert Millimeter to Micrometer

To convert from Millimeter (mm) to Micrometer (µm), multiply the value by 1,000.

Formula: µm = mm × 1,000

Reverse: mm = µm × 0.001

Step-by-Step Example

Start with your value in Millimeter. For example: 5 mm
Multiply by the conversion factor: 5 x 1,000
The result is: 5,000 µm

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.

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).

Frequently Asked Questions

How many Micrometer are in 1 Millimeter?

There are exactly 1,000 Micrometer in 1 Millimeter. This means the conversion factor from Millimeter to Micrometer is 1,000.

What is the formula to convert Millimeter to Micrometer?

The formula to convert Millimeter to Micrometer is: µm = mm × 1,000. For example, to convert 10 Millimeter to Micrometer, you would multiply 10 by 1,000.

What is a Millimeter?