Millimeter to Micrometer Converter
One Millimeter equals 1000 Micrometer (1 mm = 1000 um). Multiply a Millimeter value by 1000 to get the equivalent in Micrometer. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
um = mm × 1000
Multiply the Millimeter value by 1000 to get the equivalent value in Micrometer.
Example Conversions
1 Millimeter (mm)
1000 Micrometer (um)
5 Millimeter (mm)
5000 Micrometer (um)
10 Millimeter (mm)
10000 Micrometer (um)
25 Millimeter (mm)
25000 Micrometer (um)
100 Millimeter (mm)
100000 Micrometer (um)
Conversion Table
| Millimeter (mm) | Micrometer (um) |
|---|---|
| 0.1 | 100 |
| 0.5 | 500 |
| 1 | 1000 |
| 2 | 2000 |
| 5 | 5000 |
| 10 | 10000 |
| 25 | 25000 |
| 50 | 50000 |
| 100 | 100000 |
| 250 | 250000 |
| 500 | 500000 |
| 1000 | 1000000 |
How to Convert Manually
Use these steps to convert Millimeter values to Micrometer without the calculator.
- Write down the value in Millimeter (mm) that you want to convert.
- Multiply that value by 1000.
- For example, 10 Millimeter × 1000 = 10000 Micrometer.
- Label the result as Micrometer (um).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Millimeter and one Micrometer.
About Millimeter and Micrometer
The millimeter is one thousandth of a meter. Engineering and manufacturing drawings in metric countries are dimensioned almost exclusively in millimeters to avoid decimal points. The micrometer (micron) is one millionth of a meter, or a thousandth of a millimeter. It is the working scale of cell biology, semiconductor features, and surface-finish specifications. One Millimeter equals 1000 Micrometer (1 mm = 1000 um). Millimeter to Micrometer conversion comes up most often in engineering and CAD drawings and in manufacturing tolerances, typically when figures need restating for microscopy and cell biology.
Precision and Rounding: Length factors between metric and imperial units are exact by definition (1 ft = 0.3048 m since 1959), so any rounding error comes from display precision, not the factor. Two or three decimal places suit carpentry and DIY work; machining and surveying often require four or more.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 Millimeter equals 15000 Micrometer.
15 mm × 1000 = 15000 um
FAQ
How do I convert Millimeter to Micrometer?
Multiply the Millimeter value by 1000 to get the equivalent value in Micrometer.
What is the formula for Millimeter to Micrometer?
The formula is um = mm × 1000.
How many Micrometer are in 1 Millimeter?
1 Millimeter equals 1000 Micrometer.
Can I convert Micrometer back to Millimeter?
Yes. 1 Micrometer equals 0.001 Millimeter, and the related converter can reverse the calculation.
What are common names for Millimeter and Micrometer?
Millimeter is shown as mm and may also be searched as millimetre, millimeters, millimetres. Micrometer is shown as um and may also be searched as micron, micrometers, microns.
Was this page helpful?
Let us know if this converter met your needs.