Micrometer to Millimeter Converter
Length · unit-converter
Convert Micrometer to Millimeter with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations use SI-based definitions (international yard, nautical mile, etc.).
Calculator
From: Micrometer (um)
To: Millimeter (mm)
About Micrometer
The micrometer (micron) is one millionth of a meter. It is used in microscopy, manufacturing tolerances, and fiber optics.
About Millimeter
The millimeter is a metric unit equal to one thousandth of a meter (0.001 m). It is used for precision engineering, 3D printing, and small tolerances.
How to convert micrometers to millimeters
1 micrometer is equal to 0.001 millimeter:
1 um = (0.000001 m ÷ 0.001 m) mm = 0.001 mm
Each micrometer is defined as 0.000001 m and each millimeter as 0.001 m, so one um equals 0.000001 ÷ 0.001 mm = 0.001 mm.
Let d(um) be the numeric value of the same length measured in Micrometer (um), and d(mm) the value in Millimeter (mm). Then:
d(mm) = d(um) × (0.000001 / 0.001)
Equivalently, divide by how many um fit into one mm (meters per mm divided by meters per um):
d(mm) = d(um) ÷ 1000.00000000000011
Or: millimeter = micrometer ÷ 1000.00000000000011
Examples
Example #1: Convert 20 um to millimeter
20 um = 20 um × (0.000001/0.001) mm = 0.02 mm
20 um = 20 um ÷ 1000.00000000000011 = 0.02 mm
Example #2: Convert 50 um to millimeter
50 um = 50 um × (0.000001/0.001) mm = 0.05 mm
50 um = 50 um ÷ 1000.00000000000011 = 0.05 mm
Summary
To convert Micrometer to Millimeter, multiply the value in um by the ratio of meters per um divided by meters per mm. Equivalently: value_mm = value_um × (0.000001 / 0.001). Numerically, 1 um equals 0.001 mm.
Relationship context
Both units are metric (SI) and tied to the meter. Converting between them uses powers of ten (or simple rational factors), so the relationship is exact in decimal arithmetic. The factor from Micrometer to Millimeter is 1.000000e-3 (1 um = 0.001 mm).
Conversion tables
| Micrometer (um) | Millimeter (mm) |
|---|---|
| 0.1 | 0.0001 |
| 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 |
| Micrometer (um) | Millimeter (mm) |
|---|---|
| 10 | 0.01 |
| 20 | 0.02 |
| 30 | 0.03 |
| 40 | 0.04 |
| 50 | 0.05 |
| 60 | 0.06 |
| 70 | 0.07 |
| 80 | 0.08 |
| 90 | 0.09 |
| 100 | 0.1 |