Lowercase mu μ is the twelfth Greek letter. Type 03BC then Alt+X in Word. It is the population mean in statistics and the coefficient of friction in physics. A near-identical micro sign exists at U+00B5 for SI unit prefixes.
01 All shortcuts at a glance
| Platform | Shortcut | |
|---|---|---|
| Windows (any app) | Win+. or Win+; emoji/symbol picker, or Character Map (Win+R → charmap) |
|
| Mac | Control+Command+Space to open Character Viewer, search "Greek Small Letter Mu" |
|
| Word / Outlook | Type 03BC, then press Alt+X |
|
| Linux (IBus) | Ctrl+Shift+U, then 03bc, then Enter |
|
| HTML / CSS | μ · \03bc (CSS) |
02 Step by step, per platform
A real, followable procedure for every platform, not a thin restatement of the shortcut.
Windows
- Open Character Map: Win+R, type charmap, press Enter.
- Search or scroll for Greek Small Letter Mu (U+03BC).
- Select it, click Copy, then paste where you need it.
Mac
- Press Control+Command+Space to open the Character Viewer.
- Type "Greek Small Letter Mu" in the search field.
- Double-click the result to insert it.
Microsoft Word
- Type 03BC.
- Press Alt+X immediately after, it converts the hex code to μ.
03 Characters in this set
04 Troubleshooting & confusables
| Looks like it | But it's actually | When to use |
|---|---|---|
| µ (U+00B5) | Micro sign, the SI prefix character | For units such as µm and µF. Alt+0181 on Windows types that one, not this. |
| u (U+0075) | The Latin letter u | An ASCII workaround in code comments. Mu has a descender the letter u lacks. |
| Μ (U+039C) | Greek capital mu | Identical to a Latin M in most fonts, and a separate character. |
05 FAQ
What is the Unicode code point for mu?
Greek lowercase mu is U+03BC. The visually identical micro sign is a separate character at U+00B5, which is the one Alt+0181 produces.
Which should I use, μ or µ?
Use the micro sign U+00B5 for unit prefixes such as µg, and the Greek mu U+03BC for a mathematical variable. Unicode normalisation folds one to the other, so search behaviour varies by system.
What does μ mean in statistics?
It is the mean of a population, as opposed to the sample mean written as x with a bar. Keeping the two apart is the basis of most inferential notation.
What does it mean in physics?
Most often the coefficient of friction between two surfaces, a dimensionless number. It also denotes the reduced mass and magnetic permeability, so context matters.
What is a muon?
A subatomic particle named after the letter, heavier than an electron and short-lived. The naming follows the physics habit of borrowing Greek letters for particles.