Millimetres to micrometres – convert mm to µm
Convert millimetres to micrometres (mm to µm) to express small lengths in a much finer unit. Useful for machining tolerances, PCB design, microscopy measurements and precision engineering.
Open the interactive mm → µm converter:
Use main converter (mm → µm) or switch to µm → mmThe length converter also handles nm, m, km, inches, feet, yards, miles and more.
Quick reference: mm to µm
One millimetre is exactly 1,000 micrometres. That means: µm = mm × 1,000. Some typical values:
| Millimetres (mm) | Micrometres (µm) |
|---|---|
| 0.01 mm | 10 µm |
| 0.1 mm | 100 µm |
| 0.5 mm | 500 µm |
| 1 mm | 1,000 µm |
| 2 mm | 2,000 µm |
| 5 mm | 5,000 µm |
| 10 mm | 10,000 µm |
Why convert millimetres to micrometres?
mm to µm is handy when you:
- Describe tolerances and clearances in engineering drawings.
- Work with microscope measurements, cell sizes or material thickness.
- Convert 3D printing or PCB trace dimensions into finer units.
- Teach how SI prefixes (milli-, micro-) relate in powers of ten.
Other length converters on this site
All length conversions on the homepage follow the exact SI prefixes, so mm, µm and nm stay perfectly aligned with metres.
Page last updated: 4 December 2025.