Micro Sign (µ)

The micro sign µ is Unicode U+00B5, the SI metric prefix symbol denoting a multiplication factor of one millionth (10⁻⁶). Press Copy to put it on your clipboard, or type it with Alt + 0181 on Windows or Option + M on a Mac.

Unicode: U+00B5
HTML: µ
Windows: Alt + 0181
Mac: Option + M

How to type the micro sign (µ)

The quickest way is to press Copy above and paste. To type µ yourself, use the method for your device below. On Windows the alt code is Alt + 0181. On a Mac it is Option + M.

Windows

Hold Alt and type 0181 on the numeric keypad, then release Alt. Num Lock must be on. This uses the Windows-1252 code page, so it works in almost every Windows app.
Hold Alt and type 230 on the numeric keypad. This older code (from code page 437) works in Notepad, Word and most desktop apps.
In Word or Outlook, type 00B5 and press Alt + X. Alt + X converts the hex code before the cursor into the character, and back again.
Press Win + R, type charmap and press Enter. Tick “Advanced view”, search for Micro Sign, then Select and Copy. Character Map is built into every version of Windows.

Mac

Press Option+M. On the standard US and US-International layouts.
Press Control + Command + Space to open the Character Viewer, search for micro and double-click it.

Linux & ChromeOS

Press Ctrl + Shift + U, type b5, then press Enter or Space. Works in GTK and IBus apps (GNOME, Firefox, Chrome, LibreOffice) and on ChromeOS.
Press your Compose key, then m u. Needs a Compose key set in your keyboard settings.

iPhone & iPad

Copy µ from this page, then go to Settings → General → Keyboard → Text Replacement and add it with a shortcut such as ;micr. The shortcut then turns into the symbol as you type, in every app.

Android

Copy µ here, then open Gboard settings → Dictionary → Personal dictionary and add it with a shortcut.

Microsoft Word

Type 00B5, then press Alt + X.
Insert → Symbol → More Symbols. Set “from” to Unicode (hex), type 00B5 in “Character code” and click Insert.
On a Mac, Option+M works in Word too.

Google Docs

Insert → Special characters, then search for “micro” or draw it in the box.

Excel & Google Sheets

Enter =UNICHAR(181) in a cell. It works in Excel 2013 and later and in Google Sheets.

HTML

Write µ or µ in your HTML.

What does µ mean?

The micro sign µ (Unicode name MICRO SIGN, U+00B5) is the International System of Units (SI) metric prefix designating a factor of 10⁻⁶, or one millionth. It is used worldwide across physical science, pharmacology, and microelectronics to express tiny quantities, such as micrometres (microns, µm), microseconds (µs), and microfarads (µF). The glyph is derived from the Greek lowercase letter mu (μ). Because the micro sign was originally included in the ISO/IEC 8859-1 (Latin-1) standard at position 0xB5, Unicode maintains it as a distinct character separate from the Greek small letter mu (U+03BC). It operates alongside the ohm symbol Ω and other technical unit symbols, maintaining cross-disciplinary relevance between classic Greek letters and modern letterlike symbols.

Common uses

Electrical engineering capacitor ratings: 10 µF (microfarads)
Biology and microscopy cell dimensions: 25 µm diameter
Pharmacology medication dosages: 50 µg (micrograms, often written mcg in clinical notes)
Semiconductor manufacturing fabrication nodes and precision mechanics

Micro Sign codes for HTML, CSS and programming

Every code below produces µ. Use the HTML entity in web pages, the CSS escape in content, and the escape sequence in source code.

Codes for µ
Unicode code point	`U+00B5`
HTML entity (named)	`µ`
HTML decimal	`µ`
HTML hex	`µ`
CSS content	`content: "\B5";`
JavaScript	`"\u00B5"`
Python	`"\u00B5"`
Python (by name)	`"\N{MICRO SIGN}"`
Java / C#	`"\u00B5"`
LaTeX	`\mu`
UTF-8 bytes	`C2 B5`
UTF-16	`00B5`
URL encoded	`%C2%B5`
Windows Alt code	`Alt + 0181`
Alt code (CP437)	`Alt + 230`
Mac shortcut	`Option + M`

µ vs look-alike characters

These characters look similar to µ but have a different meaning and code. Pasting the wrong one can break search, sorting and screen readers.

Char	Name	When to use it
	Greek Mu `U+03BC`	Greek small letter mu (U+03BC), the standard letter of the Greek alphabet.
	U `U+0075`	Latin lowercase u, commonly used as an informal ASCII substitute (e.g., "uF" or "ug").
	Capital M `U+004D`	Capital M, the metric prefix for mega (10⁶, one million) rather than micro (10⁻⁶).

Symbols similar to µ

Click to copy, or open a symbol for its codes. See the full unit symbols collection.

µ character properties

Official Unicode name: MICRO SIGN
Also known as: micro symbol, mu symbol, micron sign, one millionth sign
Code point: U+00B5
Unicode block: Latin-1 Supplement (U+0080–U+00FF)
General category: Lowercase letter (Ll)
Added in: Unicode 1.1 (1993)
Plane: Basic Multilingual Plane (0)
Emoji: No, it is a text symbol

Frequently asked questions

What is the difference between µ (U+00B5) and μ (U+03BC)?

U+00B5 is the Latin-1 legacy micro sign designed as a unit prefix, while U+03BC is the lowercase Greek letter mu. In Unicode normalization form NFKC, U+00B5 decomposes to U+03BC.

Why do doctors write mcg instead of µg?

Medical guidelines often require writing "mcg" instead of "µg" because a handwritten micro sign µ can easily be misread as "mg" (milligram), creating dangerous dosing errors.

How do I type the micro sign on Windows?

Hold the Alt key and type 0181 on the numeric keypad to produce the micro sign µ.

What is the alt code for the micro sign?

On Windows, hold Alt and type 0181 on the numeric keypad to get µ. The shorter code Alt + 230 also works in most desktop apps. On a laptop without a keypad, copy it from this page or use 00B5 then Alt + X in Word.

How do I type the micro sign on a Mac?

Press Option + M. It works in every app on the US keyboard layout. You can also open the Character Viewer with Control + Command + Space and search for it.

What is the HTML code for the micro sign?

Use the named entity µ or the numeric reference µ (hex µ). All three display µ in every browser.

What is the Unicode for the micro sign?

µ is U+00B5, officially named MICRO SIGN, in the Latin-1 Supplement block. It has been part of Unicode since version 1.1 (1993).