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Micrometers to Millimeters (μm to mm)
Convert micrometers to millimeters: 1 μm = 0.001 mm. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 μm = 0.001 mm
millimeters = micrometers × 0.001 — reverse: micrometers = millimeters × 1000
The factor is derived from the SI definitions of both units (base unit: m) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.
Worked examples
- 5 μm = 0.005 mm
- 12.5 μm = 0.0125 mm
- 100 μm = 0.1 mm
Micrometers to millimeters conversion table
| Micrometers (μm) | Millimeters (mm) |
|---|---|
| 1 | 0.001 |
| 2 | 0.002 |
| 3 | 0.003 |
| 4 | 0.004 |
| 5 | 0.005 |
| 6 | 0.006 |
| 7 | 0.007 |
| 8 | 0.008 |
| 9 | 0.009 |
| 10 | 0.01 |
| 15 | 0.015 |
| 20 | 0.02 |
| 25 | 0.025 |
| 30 | 0.03 |
| 40 | 0.04 |
| 50 | 0.05 |
| 75 | 0.075 |
| 100 | 0.1 |
| 200 | 0.2 |
| 250 | 0.25 |
| 500 | 0.5 |
| 1000 | 1 |
FAQ
How many millimeters are in one micrometer?
1 μm = 0.001 mm. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.
What is the formula to convert micrometers to millimeters?
Multiply the value in micrometers by 0.001: millimeters = micrometers × 0.001. For example, 5 μm = 0.005 mm.
How do I convert millimeters back to micrometers?
Multiply by the inverse factor 1000 (micrometers = millimeters × 1000), or use the millimeters-to-micrometers page.
Related conversions
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=um&to_unit=mm - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"um","to_unit":"mm"} - Markdown: https://tttkmbb.com/conversion/micrometers-to-mm.md · JSON: https://tttkmbb.com/conversion/micrometers-to-mm.json (add
?value=for a result) · Units: /api/v1/units?quantity=length - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.