How to convert micrometers to millimeters
- Take the value in micrometers.
- Use the formula millimeters = micrometers ÷ 1,000.
- For example, 2.5 µm is 0.0025 mm.
About micrometers and millimeters
A millimeter is 1,000 micrometers, so divide µm by 1,000 to get mm. 100 µm is 0.1 mm, 25 µm is 0.025 mm and 2,500 µm is 2.5 mm. A micrometer is also called a micron, and it’s sometimes written um when the µ sign isn’t available.
Microns are used for coating and film thickness, filters, machining tolerances, cell sizes and air pollution. PM2.5 and PM10 in air quality reports are particles up to 2.5 and 10 µm across, far smaller than a millimeter.
Examples
- 2.5 µm (PM2.5, fine particles in air quality reports) is 0.0025 mm
- 10 µm (PM10 particles) is 0.01 mm
- 100 µm (roughly the thickness of a sheet of copy paper) is 0.1 mm
- 1,000 µm (one millimeter) is 1 mm
Micrometers to millimeters chart
| Micrometers (µm) | Millimeters (mm) |
|---|---|
| 0.1 | 0.0001 |
| 0.5 | 0.0005 |
| 1 | 0.001 |
| 2.5 | 0.0025 |
| 5 | 0.005 |
| 10 | 0.01 |
| 20 | 0.02 |
| 25 | 0.025 |
| 50 | 0.05 |
| 75 | 0.075 |
| 100 | 0.1 |
| Micrometers (µm) | Millimeters (mm) |
|---|---|
| 150 | 0.15 |
| 200 | 0.2 |
| 250 | 0.25 |
| 500 | 0.5 |
| 750 | 0.75 |
| 1,000 | 1 |
| 1,500 | 1.5 |
| 2,000 | 2 |
| 5,000 | 5 |
| 10,000 | 10 |