Micrometres to millimetres – convert µm to mm
Convert micrometres to millimetres (µm to mm) to turn tiny dimensions into more familiar millimetre values. Great for summarising microscope measurements, PCB features, film thickness and precision parts.
Open the interactive µm → mm converter:
Use main converter (µm → mm) or switch to mm → µmFrom the main length converter you can also jump between nm, mm, cm, m, km, inches, feet and miles.
Quick reference: µm to mm
One micrometre is 0.001 millimetres. So: mm = µm ÷ 1,000. Some examples:
| Micrometres (µm) | Millimetres (mm) |
|---|---|
| 10 µm | 0.01 mm |
| 50 µm | 0.05 mm |
| 100 µm | 0.10 mm |
| 250 µm | 0.25 mm |
| 500 µm | 0.50 mm |
| 1,000 µm | 1.00 mm |
| 2,000 µm | 2.00 mm |
Why convert micrometres to millimetres?
µm to mm is useful when you:
- Summarise microscopic measurements for non-specialist audiences.
- Check whether fine details fit within millimetre-scale tolerances.
- Convert microscope or SEM outputs into everyday units for reports.
- Show how micro-scale features compare with millimetre grid spacing.
Other length converters on this site
All SI prefix conversions (m, mm, µm, nm) on the homepage are based on exact powers of ten, so you can move cleanly up and down the scale.
Page last updated: 4 December 2025.