How to type Alt+230
- Make sure Num Lock is on.
- Hold down the Alt key.
- Type 230 on the numeric keypad. The number row above the letters will not work.
- Release Alt. The mu symbol μ appears.
Alt+230 is a classic code from the CP437 table used by the original IBM PC, which is why there is no leading zero. This symbol does not exist on the Windows-1252 table, so the classic code is the only Alt code for it.
On a laptop without a numpad
Press Win+. to open the emoji panel, pick the Symbols tab and search for "mu". Or open Character Map from the Start menu. In Microsoft Word you can type 03BC followed by Alt+X. Some laptops have a hidden numpad on the J, K, L, U, I and O keys that activates with Fn.
On a Mac
Alt codes do not exist on macOS and this symbol has no dedicated shortcut. Open the Character Viewer with Control+⌘+Space, search for "mu" and double-click it.
In HTML and code
Use μ in HTML, "\03BC" in CSS and "\u03BC" in JavaScript. See the Mu Symbol guide for every platform.
Frequently asked questions
What does Alt+230 type?+
Alt+230 types the mu symbol, μ (Unicode U+03BC). Hold Alt, type 230 on the numeric keypad, then release Alt.
Why do I need the code without a zero?+
Alt+230 is a classic CP437 code from the original IBM PC character set. It has no leading zero.
Alt+230 does not work. Why?+
Check that Num Lock is on and that you are using the numeric keypad rather than the number row. Laptops without a numpad cannot enter Alt codes: use Win + . for the symbol panel, Character Map, or copy the symbol from this page.
How do I type μ on a Mac?+
Alt codes do not work on macOS. Open the Character Viewer with Control + Command + Space, search for "mu", and double-click the symbol, or copy it from this page.