Length and Area
mmtoμm
Convert millimetres (mm) to micrometres (μm).
Factor1 mm = 1000 μm
Converter
mm
Accepts numbers or expressions, e.g. 150 + 14.7
Result
μm
Rendered to 6 significant figures.
Formula
Formula
μm = mm × 1000
Multiply any value in millimetres by 1000 to obtain the value in micrometres.
Worked example
Convert 1 mm to μm.
- 01Start with 1 mm.
- 02Multiply by the conversion factor: 1 × 1000 = 1000 μm.
Result1 mm = 1000 μm
Conversion table
| mm | μm |
|---|---|
| 1 | 1000 |
| 2 | 2000 |
| 5 | 5000 |
| 10 | 10000 |
| 20 | 20000 |
| 50 | 50000 |
| 100 | 1.0000e+5 |
| 200 | 2.0000e+5 |
| 500 | 5.0000e+5 |
| 1000 | 1.0000e+6 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from mm to μm?
1 mm equals 1000 μm. To convert, multiply the value in millimetres by 1000.
How do I convert 1 mm to μm?
1 mm = 1000 μm. For any value, multiply by 1000.
How do I convert μm back to mm?
Divide by the same factor — or equivalently, multiply by 0.001. So 1 μm = 0.001 mm.
When would I need to convert millimetre to micrometre?
Length conversions appear in piping, layout, and mechanical drawings — particularly when reconciling imperial fittings or instrument lengths with metric plant drawings.
Is the conversion exact?
Yes. Both mm and μm are defined by exact SI relationships, so the displayed factor is exact (any rounding shown is only for display).