Short answer: Most statistics symbols are ordinary Greek letters — μ is 03BC then Alt + X in Word. But x̄ and p̂ are not single characters. They’re a letter plus a combining mark: type x, then 0304, then Alt + X. That one fact explains why you’ve never found “the x-bar symbol” in a character picker.
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Got a symbol from a textbook PDF and not sure which character it is? The Symbol Identifier will name it and give you every way to type it.
The population vs sample pairs
Almost every symbol in statistics comes in a pair — a Greek letter for the population parameter, a Latin letter for the sample statistic. Getting the two mixed up is a marking error, so it’s worth reading the pairs together rather than looking symbols up one at a time.
| Quantity | Population | Sample | Sample is… |
|---|---|---|---|
| Mean | μ (U+03BC) | x̄ | x + combining macron |
| Standard deviation | σ (U+03C3) | s | plain letter |
| Variance | σ² | s² | letter + superscript two |
| Proportion | p | p̂ | p + combining circumflex |
| Correlation | ρ (U+03C1) | r | plain letter |
| Size | N | n | plain letter |
| Regression slope | β (U+03B2) | b | plain letter |
The Greek half of that table is covered in more depth in the Greek alphabet, and μ and σ have their own guides at the mu symbol and the sigma symbol.
Quick reference
| Symbol | Name | Code point | Word | HTML |
|---|---|---|---|---|
| μ | Greek small letter mu | U+03BC | 03BC + Alt + X | μ |
| σ | Greek small letter sigma | U+03C3 | 03C3 + Alt + X | σ |
| Σ | Greek capital letter sigma | U+03A3 | 03A3 + Alt + X | Σ |
| ∑ | N-ary summation | U+2211 | 2211 + Alt + X | ∑ |
| ρ | Greek small letter rho | U+03C1 | 03C1 + Alt + X | ρ |
| χ | Greek small letter chi | U+03C7 | 03C7 + Alt + X | χ |
| β | Greek small letter beta | U+03B2 | 03B2 + Alt + X | β |
| α | Greek small letter alpha | U+03B1 | 03B1 + Alt + X | α |
| λ | Greek small letter lamda | U+03BB | 03BB + Alt + X | λ |
| ∼ | Tilde operator | U+223C | 223C + Alt + X | ∼ |
| ≈ | Almost equal to | U+2248 | 2248 + Alt + X | ≈ |
| ≠ | Not equal to | U+2260 | 2260 + Alt + X | ≠ |
| ≤ | Less-than or equal to | U+2264 | 2264 + Alt + X | ≤ |
| ≥ | Greater-than or equal to | U+2265 | 2265 + Alt + X | ≥ |
| ± | Plus-minus sign | U+00B1 | 00B1 + Alt + X | ± |
| ∝ | Proportional to | U+221D | 221D + Alt + X | ∝ |
| √ | Square root | U+221A | 221A + Alt + X | √ |
| ² | Superscript two | U+00B2 | 00B2 + Alt + X | ² |
| ₀ | Subscript zero | U+2080 | 2080 + Alt + X | ₀ |
Note that Greek letters have no Windows Alt codes — the legacy Alt code table stops at 255 and these are all above it. ± and ² are the exceptions, at Alt + 0177 and Alt + 0178.
x̄ and p̂ are two characters
This is the part that sends people round in circles. There is no single Unicode character for “x with a bar over it.” What you’re looking at is a base letter followed by a combining mark, and the renderer stacks the second on top of the first:
| You want | Build it from | Code points |
|---|---|---|
| x̄ (x-bar) | x + combining macron | U+0078 U+0304 |
| ȳ (y-bar) | y + combining macron | U+0079 U+0304 |
| p̂ (p-hat) | p + combining circumflex | U+0070 U+0302 |
| x̃ (x-tilde, the median) | x + combining tilde | U+0078 U+0303 |
| σ̂ (sigma-hat) | σ + combining circumflex | U+03C3 U+0302 |
One exception is worth knowing, because it explains why these sometimes render unevenly: ȳ does have a precomposed single character — ȳ U+0233 LATIN SMALL LETTER Y WITH MACRON — while x̄ has none. Fonts usually draw a precomposed character better than a stacked pair, so y-bar can look cleaner than x-bar in the same document. Both sequences are correct; they just take different paths through the font.
The order matters: base letter first, mark second. The mark attaches to whatever character precedes it, so typing the mark first gives you a stray accent floating on a dotted circle.
Two practical consequences. Your cursor treats x̄ as two positions, so one press of backspace removes the bar and leaves the x. And a search for “x̄” won’t match text where someone used a different construction — which is common, because plenty of people fake it with an underline or an image.
Windows
- In Word, for a single character: type the hex code then Alt + X.
03BC+ Alt + X gives μ. For x̄, typex, then0304, then Alt + X — the macron lands on the x. - In Word, for a formula: press Alt + = to open an equation field, then type
\bar xfollowed by a space. The equation editor builds it properly, which is the better option for anything that’s genuinely mathematics rather than a symbol in a sentence. - Anywhere else: copy from the keys above, or use Character Map (
charmap, Advanced view, Go to Unicode).
Alt + X is a Word feature and won’t convert in a browser or in Excel. And there are no legacy Alt codes for the Greek letters — see symbols in Word.
Mac
No Option shortcut exists for the Greek letters or the combining marks.
- Unicode Hex Input — enable it in System Settings → Keyboard → Input Sources, then hold Option and type 03BC. For x̄: type
xnormally, then Option +0304. - Character Viewer — Control + Command + Space, then search “mu” or “greek small letter mu”.
Linux
Ctrl + Shift + U, type 03bc, then Enter or Space — the GNOME-documented sequence. Combining marks work the same way: type the base letter, then the sequence for 0304. More in typing symbols on Linux.
Excel and Google Docs
- Excel:
=UNICHAR(956)gives μ. For x̄, concatenate:="x"&UNICHAR(772). It works, but Excel’s rendering of combining marks varies by font — check it before building a whole sheet on it. A cleaner route for headers is to type the letter and apply the overline border to the cell. See symbols in Excel. - Google Docs: Insert → Special characters and search “mu”, or open Insert → Equation and type
\barthenx. The equation editor is the reliable path here too. See symbols in Google Docs.
LaTeX, HTML and code
In LaTeX the accented forms have proper commands, which is why statistical writing so often ends up there:
latex
\bar{x} \quad \hat{p} \quad \tilde{x} \quad \mu \quad \sigma^2 \quad \chi^2 \quad \sum_{i=1}^{n}More in LaTeX math symbols.
In HTML, the combining mark follows the base character just as it does in a document:
html
<p>Sample mean: x̄</p> <!-- x + U+0304 -->
<p>Sample proportion: p̂</p> <!-- p + U+0302 -->
<p>Population mean: μ</p>For real equations on the web, MathML or a maths renderer will set them better than raw characters — combining marks are positioned by the font, and the result drifts between typefaces.
Three lookalikes that matter
Σ is not ∑. The Greek capital sigma Σ U+03A3 is a letter. The summation operator ∑ U+2211 N-ARY SUMMATION is a mathematical symbol, and it’s the correct one in a formula. They look nearly identical in many fonts and behave differently in equation layout, search and screen readers.
μ is not µ. Greek small letter mu is U+03BC. There’s also µ U+00B5 MICRO SIGN — a legacy compatibility character from the days when a byte had to serve for “micro”. Use U+03BC for the population mean. This one bites often, because Alt + 0181 and the micro sign in older fonts both give you U+00B5.
σ is not ς. Greek has a separate final sigma ς U+03C2 used at the end of a word. It is never the standard deviation. Some Greek keyboard layouts produce it depending on position.
If you’re unsure which one is sitting in your document, paste it into the Symbol Identifier.
Accessibility
Screen readers announce these by Unicode name, so μ is read as “greek small letter mu” rather than “mu” or “the population mean”. Combining sequences are worse: x̄ is typically announced as “x” followed by “combining macron”, which tells a listener nothing useful.
For anything where the meaning matters, write the term in words on first use — “the sample mean x̄” — and use proper equation markup rather than raw characters for formulas. How screen readers pronounce symbols covers the pattern.
Troubleshooting
| Problem | Fix |
|---|---|
| The bar sits in the wrong place | Combining marks are positioned by the font. Try a font with good coverage, or use the equation editor. |
| Backspace deletes the bar, not the letter | Expected — x̄ is two code points. Press backspace twice. |
| Can’t find x̄ in the character picker | It isn’t a character. Build it from x + U+0304. |
| Alt + 0181 gives µ, not μ | That’s the micro sign U+00B5. Use 03BC + Alt + X for Greek mu. |
| Greek letter has no Alt code | Correct — legacy Alt codes stop at 255. Use hex + Alt + X, or copy. |
| Symbol shows as a box | Font gap. Use a font with Greek coverage such as Cambria, Calibri or Noto Serif. |
| Mark appears on a dotted circle ◌ | You typed the combining mark first. Base letter, then mark. |
Recap
| You need | Do this |
|---|---|
| A Greek letter | Hex + Alt + X, or copy above |
| x̄ or p̂ in a sentence | Letter, then 0304 / 0302, then Alt + X |
| x̄ in a real equation | Alt + =, then \bar x |
| Anything in Excel | =UNICHAR(956), or cell overline border |
| Anything on the web | μ, x̄ |
| Anything in LaTeX | \mu, \bar{x}, \hat{p} |
Frequently asked questions
How do I type the x-bar symbol?
It isn’t a single character. Type x, then 0304, then press Alt + X in Word — that’s the combining macron landing on the x. In an equation field, press Alt + = and type \bar x instead.
What’s the difference between μ and µ?
μ is U+03BC, the Greek letter mu, and it’s the correct character for the population mean. µ is U+00B5, the micro sign, a legacy compatibility character. They look almost identical but sort, search and read differently.
Is Σ the same as the summation sign?
No. Σ is U+03A3, the Greek capital letter. The summation operator is ∑ U+2211 N-ARY SUMMATION, and that’s the correct one in a formula.
Why does backspace only delete the bar over my x?
Because x̄ is two code points — the letter and the combining mark. Each backspace removes one. That’s normal behaviour, not a fault.
Do Greek letters have Windows Alt codes?
No. The legacy Alt code table stops at 255 and every Greek letter sits above it. Use the hex code followed by Alt + X in Word, or copy the character.
How do I write x̄ in Excel?
Use ="x"&UNICHAR(772) to concatenate the letter with the combining macron. Rendering varies by font, so for column headers the overline cell border is often cleaner.
Written by Igor R. Tested on Windows 11, macOS, Linux, Word, Excel, Google Docs and LaTeX. Last updated September 2026. Symbol code points follow the Unicode Standard.