The theta symbol is θ. Windows has no standard Alt code for it, so the quickest routes are typing 03B8 in Word and pressing Alt+X, or 03B8 then Alt+X in Word on the numeric keypad in a Unicode-aware app.
On a Mac, open the Character Viewer with Control+Command+Space and search for theta. Both give you the lowercase Greek θ.
Theta symbol quick reference
| Method | Input | Works in |
|---|---|---|
| Windows Alt code | No standard Alt code for θ | — |
| Windows, Unicode-aware apps | 03B8 then Alt+X in Word (decimal, numeric keypad) | Word, WordPad, similar |
| Mac | No shortcut; Character Viewer (Ctrl+Cmd+Space) | Most Mac apps |
| Word / Outlook / OneNote | Type 03B8 (hex), then Alt+X | Word, Outlook, OneNote |
| Excel & Google Sheets | =UNICHAR(952) | Spreadsheets |
| Google Docs | Insert → Special characters, search “theta” | Google Docs |
| Chromebook / Linux | Ctrl+Shift+U, 03b8, Enter | ChromeOS, Linux |
| HTML | θ · θ · θ | Web pages |
| CSS | \03B8 | Web pages |
| LaTeX | \theta | Math typesetting |
| Unicode code point | U+03B8 (decimal 952) | Universal |
03B8 then Alt+X in Word uses the decimal code point (952). Word’s Alt+X, the Chromebook shortcut, and the CSS escape all use the hexadecimal form (03B8). It’s the same character written two ways, so don’t feed the hex into an Alt code or the decimal into Alt+X.
Type θ on Windows
Windows has no classic Alt code for theta. The modern Western table (the Alt+0nnn codes) stops before the Greek letters, and there is no legacy code for it either. You have two dependable options, and one shortcut that only works in some apps.
03B8 then Alt+X in Word in Unicode-aware apps
- Turn on Num Lock.
- Hold Alt and type 952 on the numeric keypad.
- Release Alt.
This fires in Word, WordPad, and other Unicode-aware programs, but not everywhere. It needs a real numeric keypad, so the number row along the top of the keyboard will not trigger it. If nothing appears, use Character Map instead.
Character Map
- Open the Start menu, type “Character Map,” and open it.
- Tick Advanced view, then type
thetain the search box (or set Go to Unicode to03B8). - Select θ, click Select, then Copy, and paste.
The Win + . emoji panel is built for emoji and doesn’t reliably list Greek letters, so Character Map is the faster on-screen route here. If you use Alt codes often, the Alt code finder tool looks up any character by name or number.
Type θ on Mac
macOS has no Option-key shortcut for theta and no Alt codes at all. The Character Viewer is the standard route.
- Press Control + Command + Space to open the Character Viewer.
- Type “theta” in the search box.
- Double-click θ to insert it, or drag it into your document.
For heavy use, add the Greek input source: System Settings → Keyboard → Text Input → Edit → +, then add Greek. On that layout θ sits on the U key, and you switch layouts from the input menu in the menu bar.
Type θ in Word and PowerPoint
Alt+X
- Type
03B8where you want the symbol. - Press Alt + X. The code flips to θ.
To reverse it, place the cursor just after θ and press Alt+X again. This works in Word, Outlook, and OneNote. It does not work in PowerPoint or Excel.
Insert Symbol
- Insert tab → Symbol → More Symbols.
- Set the subset to Greek and Coptic.
- Select θ and click Insert.
The same Insert → Symbol route works in PowerPoint. Since Alt+X does not, this is how you get θ onto a slide. Inside a Word equation field (Alt + =), typing \theta then Space also converts to θ, and \Theta gives the uppercase Θ.
Type θ in Excel and Google Sheets
Spreadsheets don’t use Alt+X, so reach for a formula. =UNICHAR(952) returns θ in both Excel and Google Sheets. To lock it in as plain text, copy the cell and use Paste Special → Values.
Excel also has Insert → Symbol with the Greek and Coptic subset. Google Sheets has no Insert Symbol menu at all, so UNICHAR or a paste is the way. If you paste or use an OS-level shortcut inside a Sheets cell, press F2 first to enter edit mode.
Type θ in Google Docs
- Insert → Special characters.
- Type “theta” in the search box, or draw the shape in the sketch pad.
- Click θ to drop it into the document.
Google Docs also has an equation editor (Insert → Equation). Type \theta followed by a space and it converts to θ, and \Theta gives the uppercase Θ.
Type θ on iPhone and Android
Neither phone keyboard has a theta key by default. Add a Greek keyboard for regular use. On iPhone: Settings → General → Keyboard → Keyboards → Add New Keyboard → Greek.
On Android with Gboard: Settings → Languages → Add keyboard → Greek. Switch to it with the globe key, and θ is on the layout.
For occasional use, set a text replacement so a short trigger expands to θ, or just copy θ from the button near the top of this page.
Type θ on a Chromebook
ChromeOS has no Alt codes, so use the Unicode shortcut.
- Put the cursor where you want θ.
- Hold Ctrl + Shift + U. A small underlined u appears.
- Type
03b8(hex, no U+ prefix). - Press Enter or Space.
Newer Chromebooks also have a symbol picker at Launcher + Shift + Space, or a dedicated Quick Insert key. Some websites intercept Ctrl+Shift+U; if nothing happens, paste θ instead.
Type θ in Notion, Slack, Discord, and Canva
None of these apps has a built-in theta shortcut, so the reliable move is to paste θ. In Notion you can also use an inline equation (type /math or an equation block) and enter \theta, which renders as θ.
Slack and Discord have no symbol picker, so paste it. To avoid re-pasting, set an OS-level text replacement, covered in the FAQ below. Canva is the same: click into a text box and paste θ.
Type θ in HTML and CSS
For web pages, three forms all render θ: the named entity θ, the decimal θ, and the hex θ. Note the uppercase entity Θ gives Θ, a different character.
In CSS content, use the escape \03B8, for example content: "\03B8";. In JavaScript strings, the same character is "\u03B8".
Troubleshooting θ
- 03B8 then Alt+X in Word does nothing: it only works in Unicode-aware apps and needs Num Lock on with a real numeric keypad. In a plain text field or browser box, use Character Map or paste instead.
- It shows as a box (□) or question mark: your font lacks the Greek glyph. Switch to Arial, Calibri, Times New Roman, or another common font, all of which include θ.
- You typed a lookalike: θ has an oval body with a horizontal bar. The empty set ∅ (U+2205) is a perfect circle with a diagonal slash. The Danish letter ø is an o with a slash. Phi φ is a circle with a vertical line through it.
- Cursive variant: some fonts and journals use ϑ (U+03D1) for theta. If your document mixes both shapes, you likely pasted from a source that used the variant.
What θ is used for
- Angles: θ is the default label for an angle in trigonometry and geometry.
- Coordinates: the polar (r, θ) and spherical (r, θ, φ) systems.
- Physics: angular displacement, phase angle, and wave equations.
- Statistics: θ often denotes an unknown parameter being estimated.
- Neuroscience: theta waves (4–8 Hz) in EEG readings.
Related symbols people mix up with theta
- Phi (φ) — a circle with a vertical stroke, paired with θ in spherical coordinates.
- Psi (ψ), a trident shape, the wavefunction symbol in quantum mechanics.
- Delta (Δ) — the uppercase triangle for change or difference.
- Beta (β), looks like a German ß; used for coefficients and angles.
- Sigma (Σ) — the summation sign.
For the whole set of codes in one place, see the full Alt code list, or browse more math and science symbols.
Frequently asked questions
What is the difference between θ and ϑ?
Both are lowercase theta. θ (U+03B8) is the standard letter, while ϑ (U+03D1) is a cursive or “script” variant used in some physics texts and older typesetting.
They mean the same letter but are separate Unicode characters, so find-and-replace treats them differently. In LaTeX, \theta gives θ and \vartheta gives ϑ.
How do I type an uppercase Theta (Θ)?
Uppercase Theta is Θ, code point U+0398 (decimal 920). In Word, type 0398 then Alt+X. On the web use Θ or Θ.
In a spreadsheet, =UNICHAR(920). On Chromebook, Ctrl+Shift+U then 0398.
I don’t have a numeric keypad, how do I type theta on a laptop?
Skip 03B8 then Alt+X in Word, since it needs a real keypad, and use a method that doesn’t. Type 03B8 then Alt+X in Word, use =UNICHAR(952) in a spreadsheet, or copy θ from the button at the top of this page. Turning on your laptop’s on-screen keyboard with a numpad works too, but it’s slower.
Does theta work in the Google Docs equation editor?
Yes. Go to Insert → Equation, then type \theta followed by a space and it converts to θ; \Theta gives the uppercase Θ. You can also pick it from the Greek letters menu in the equation toolbar.
How can I make “theta” auto-replace with θ?
Set a text replacement so you never repeat these steps. In Word: File → Options → Proofing → AutoCorrect Options, add θ as the replacement for a trigger like \theta. On Mac: System Settings → Keyboard → Text Replacements.
On iPhone: Settings → General → Keyboard → Text Replacement. On Android Gboard: Settings → Dictionary → Personal dictionary. Paste θ as the target and pick a trigger you won’t type by accident.