How to convert micrometers to millimeters
mm = µm × 0.001Multiply the value in micrometers by 0.001. To go the other way, multiply by 1,000 (or divide by 0.001).
A micrometer is smaller than a millimeter: it takes 1,000 micrometers to make one millimeter.
Worked examples
- 1 micrometer1 µm × 0.001 = 0.001 mm
- 5 micrometers5 µm × 0.001 = 0.005 mm
- 10 micrometers10 µm × 0.001 = 0.01 mm
- 20 micrometers20 µm × 0.001 = 0.02 mm
- 100 micrometers100 µm × 0.001 = 0.1 mm
Micrometers to millimeters conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Micrometers (µm) | Millimeters (mm) |
|---|---|
| 0.1 µm | 0.0001 mm |
| 0.25 µm | 0.00025 mm |
| 0.5 µm | 0.0005 mm |
| 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 |
| Micrometers (µm) | Millimeters (mm) |
|---|---|
| 12 µm | 0.012 mm |
| 15 µm | 0.015 mm |
| 20 µm | 0.02 mm |
| 25 µm | 0.025 mm |
| 30 µm | 0.03 mm |
| 40 µm | 0.04 mm |
| 50 µm | 0.05 mm |
| 75 µm | 0.075 mm |
| 100 µm | 0.1 mm |
| 250 µm | 0.25 mm |
| 500 µm | 0.5 mm |
| 1,000 µm | 1 mm |
About the units
Micrometer (µm)
One millionth of a metre, often called a micron. Human hair is roughly 50–100 µm across, and filter and particle sizes are given in micrometres. One micrometer equals 0.000001 meters (m).
Millimeter (mm)
One thousandth of a metre. Millimetres are the standard unit on engineering drawings, rulers and rainfall gauges; a credit card is about 0.76 mm thick. One millimeter equals 0.001 meters (m).
Frequently asked questions
How many millimeters are in one micrometer?
There are 0.001 millimeters in one micrometer, and this value is exact by definition.
How do I convert micrometers to millimeters?
Multiply the number of micrometers by 0.001. For example, 10 µm × 0.001 = 0.01 mm.
How many micrometers are in one millimeter?
One millimeter equals 1,000 micrometers. That is the reverse factor, 1 ÷ 0.001.
What is 10 micrometers in millimeters?
10 µm = 0.01 mm.
Is this µm to mm converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.