How to Type the Micro Symbol (µ) on a Keyboard

One of the more useful scientific symbols — here’s the fastest method on every platform

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The micro symbol µ (Unicode U+00B5) is the SI prefix meaning one millionth — µm for micrometers, µg for micrograms, µs for microseconds, µF for microfarads.

It appears constantly in scientific, medical, engineering, and electronics writing.

It’s not on a standard US keyboard but it’s one of the more accessible special characters — most platforms have it fairly close to the surface.

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An Important Distinction: µ vs μ

Two different Unicode characters look nearly identical and are frequently confused:

µ — the micro sign (U+00B5). The official SI prefix symbol for micro. Encoded in the Latin-1 Supplement block. This is the correct character to use in scientific notation — µm, µg, µA, and so on.

μ — lowercase mu, the Greek letter (U+03BC). The Greek letter that the micro sign is derived from. Used in mathematics and physics as a variable or constant — coefficient of friction, magnetic permeability, mean of a distribution.

In most fonts they look identical and the difference rarely matters in practice. For strict technical publishing and SI unit notation, µ (the micro sign) is technically correct. For mathematical variables and Greek letter contexts, μ (mu) is appropriate. For everyday use the distinction is negligible.

The methods below cover both. Where shortcuts differ between them, both are noted.

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Windows

Method 1: Alt Code

Hold Alt and type 0181 on the numeric keypad. Release Alt and µ appears.

• Num Lock must be on
• Use the numeric keypad only — not the number row
• Doesn’t work on laptops without a dedicated numpad

For the Greek letter μ (mu): hold Alt and type 956 on the numpad.

Method 2: Character Map

Search for Character Map in the Start menu. Find µ in the Latin-1 Supplement block (U+00B5) or μ in the Greek block (U+03BC). Copy and paste. Works on any Windows machine.

Method 3: System-Wide Text Expansion

Use PhraseExpress, AutoHotkey, or Espanso to map a trigger like \mu or uu to µ system-wide. Works in every application without remembering Alt codes.

A simple AutoHotkey script:

::\mu::µ

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Mac

Method 1: Keyboard Shortcut

Press Option + M to type µ instantly.

This is the method to remember on Mac. M for micro — logical, easy to remember, works in every application with no setup required.

Method 2: Character Viewer

Press Control + Command + Space to open the Character Viewer. Search “micro” for µ or “mu” for μ and double-click to insert.

Method 3: Text Replacement

Go to System Settings → Keyboard → Text Replacements and map a trigger like \mu to µ. Works system-wide across every Mac app.

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iPhone and iPad

Method 1: Long Press the M Key

Tap and hold the M key on the iOS keyboard. On many iOS keyboard configurations, µ or μ appears as a long-press option. Slide to it and release.

Check this first — if your keyboard shows it on long press, no setup is needed.

Method 2: Text Replacement

Go to Settings → General → Keyboard → Text Replacement. Add µ as the phrase and a trigger like \mu or uu as the shortcut. Auto-expands in any text field across iOS after setup.

This is the most reliable method for regular micro symbol use on iOS — a one-time setup that works everywhere.

Method 3: Greek Keyboard

Go to Settings → General → Keyboard → Keyboards → Add New Keyboard and add Greek. With Greek active, μ (mu) is on the M key. For the micro sign specifically, the text replacement approach is more targeted.

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Android

Method 1: Long Press the M Key

On Gboard and many Android keyboards, tap and hold the M key. µ or μ often appears as a long-press option. Slide to it and release.

Try this first — it works on most Android keyboards without any setup.

Method 2: Gboard Symbol Search

In Gboard, tap the G logo and use the search function. Type “micro” for µ or “mu” for μ and tap to insert.

Method 3: Add Greek Keyboard

In Gboard settings, go to Languages → Add Keyboard and add Greek. With Greek active, μ is on the M key directly.

Method 4: Text Replacement

In Gboard settings, go to Dictionary → Personal Dictionary, select your language, and add µ with shortcut \mu. Expands automatically as you type.

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Chromebook

Method 1: Unicode Input

For micro sign µ: press Ctrl + Shift + U, type 00b5, then press Enter or Space.

For Greek mu μ: press Ctrl + Shift + U, type 03bc, then press Enter or Space.

Method 2: Special Characters Picker

Press Search + Shift + Space to open the emoji and special characters panel. Search “micro” or “mu” and select the appropriate symbol.

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Linux

Method 1: Unicode Input

For µ: press Ctrl + Shift + U, type 00b5, then press Enter.

For μ: press Ctrl + Shift + U, type 03bc, then press Enter.

Works consistently across most Linux distributions.

Method 2: Compose Key

With a Compose key configured, the sequence Compose + m + u produces µ on many Linux configurations. Check your specific compose key table as sequences vary by distribution.

Method 3: Greek Keyboard Layout

Add the Greek keyboard layout through your input method settings. μ is on the M key with the Greek layout active.

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Microsoft Word (Any Platform)

Method 1: Alt + X

For micro sign µ: type 00B5 then immediately press Alt + X.

For Greek mu μ: type 03BC then immediately press Alt + X.

Word converts the Unicode code point to the symbol instantly.

Method 2: Insert Symbol With AutoCorrect

Go to Insert → Symbol → More Symbols. Find µ in Latin-1 Supplement or μ in Greek and Coptic. Click AutoCorrect and set a trigger like \mu that Word converts automatically. From this point on, typing \mu followed by a space converts to µ in all Word documents.

Method 3: Equation Editor

For scientific documents where µ appears in formal unit notation or equations, press Alt + = to open an equation field and type \mu followed by Space. Word’s equation editor renders properly formatted µ in math mode — correct for writing unit expressions like µm and µF in equations.

Method 4: Alt Code

Hold Alt and type 0181 on the numpad for µ — same as the standard Windows method.

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Google Docs

Option + M on Mac works inside Google Docs exactly as it does everywhere else. The Alt code works on Windows inside Docs.

For equations, go to Insert → Equation and type \mu followed by Space — Google’s equation editor renders it correctly.

Go to Insert → Special Characters, search “micro sign,” and click to insert for occasional use without needing to remember shortcuts.

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LaTeX

In LaTeX, the micro prefix and the Greek letter mu are both typed as \mu in math mode:

latex

% Greek letter mu as a variable
The coefficient of friction is $\mu = 0.3$.

% For SI units with the micro prefix, use the siunitx package
\usepackage{siunitx}
\SI{5}{\micro\meter}   % produces 5 µm
\SI{10}{\micro\gram}   % produces 10 µg

For professional scientific typesetting in LaTeX, the siunitx package is strongly recommended for SI units — it handles micro prefix formatting correctly and consistently rather than relying on manually typed µ characters.

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HTML and Web Development

html

<!-- Micro sign (U+00B5) -->
&micro;       <!-- named entity -->
&#181;        <!-- decimal -->
&#xB5;        <!-- hex -->
µ             <!-- direct character -->

<!-- Greek mu (U+03BC) — no named HTML entity -->
&#956;        <!-- decimal -->
&#x03BC;      <!-- hex -->
μ             <!-- direct character -->

The named entity µ is the cleanest option for HTML — it specifically references the micro sign rather than the Greek letter.

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In Electronics and Engineering

µ appears constantly in electronics — component values are frequently expressed in micro units. Common expressions:

• µF — microfarads (capacitor values)
• µH — microhenries (inductance)
• µA — microamps (small current)
• µV — microvolts
• µm — micrometers (semiconductor geometries, optical measurements)
• µs — microseconds (timing)

In electronics documentation and datasheets, the lowercase u is frequently used as a substitute for µ — uF, uH, uA — because µ wasn’t always available in older text systems and terminals. This substitution is widely understood in electronics contexts even if typographically incorrect. If you’re writing formal documentation or anything that will be properly typeset, use the actual µ symbol.

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Quick Reference Table

Symbol	Platform	Fastest Method	Shortcut
µ	Windows	Alt code (numpad)	Alt + 0181
µ	Mac	Keyboard shortcut	Option + M
µ	iPhone / iPad	Long press M key	Hold M, slide to µ
µ	Android	Long press M key	Hold M, slide to µ
µ	Chromebook	Unicode input	Ctrl + Shift + U, 00b5
µ	Linux	Unicode input	Ctrl + Shift + U, 00b5
µ	Microsoft Word	Code conversion	Type 00B5 then Alt + X
µ	LaTeX	Math command	\mu in math mode
µ	HTML	Named entity	µ

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The Bottom Line

On Mac, Option + M is the most memorable shortcut for any scientific symbol — M for micro, nothing to memorize beyond that. On mobile, the long press on the M key covers it without any setup on most keyboards. On Windows, Alt + 0181 works reliably with a numpad.

For anyone writing regularly about electronics, biology, chemistry, or any field where micro-scale measurements appear frequently, a text expansion shortcut mapping \mu or uu to µ is worth the two minutes to configure — it works system-wide and makes the correct symbol no harder to type than its informal substitute.

Option + M on Mac. Alt + 0181 on Windows. Long press M on mobile. And µ in HTML — one of the more accessible scientific symbols once you know where to look.