Theta Symbol Θ θ — Copy, Paste and Type It

Q: How do I type the theta symbol on a keyboard?

On Windows, press Win + . → Symbols → Greek, or in Microsoft Word type 03B8 and press Alt + X; the classic Alt code Alt + 233 types Θ. On a Mac, switch to the Greek keyboard and press U (Shift + U for the capital). Or simply copy it from the top of this page.

Q: What is the LaTeX command for theta?

Use \theta for lowercase θ and \Theta for capital Θ, inside math mode: $\theta$.

Q: What is the Unicode and HTML code for theta?

Lowercase θ is U+03B8, written in HTML as θ or θ. Capital Θ is U+0398, written Θ or Θ.

The theta symbol is the 8th letter of the Greek alphabet, written θ in lowercase and Θ in uppercase. It is pronounced /ˈθiːtə/ (“THAY-tuh or THEE-tuh”). Click a symbol to copy it.

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Copy the theta symbol

Greek small letter theta U+03B8 · The lowercase letter

Greek capital letter Theta U+0398 · The uppercase letter

Greek theta symbol (script theta) U+03D1 · The cursive ϑ form, used as a separate variable in math and physics.

Greek capital theta symbol U+03F4 · A rarely needed variant of capital Θ.

Empty set U+2205 · Set theory ∅. Not theta, not phi.

Dashed boxes are look-alikes that are not the Greek letter — listed so you can tell them apart.

Theta codes — Unicode, HTML, LaTeX and Alt codes

Char	Unicode	HTML entity	HTML decimal	HTML hex	CSS	JavaScript	LaTeX	Windows	Mac
θ	`U+03B8`	`θ`	`θ`	`θ`	`\03B8`	`\u03B8`	`\theta`	`03B8` then `Alt + X` (Word)	Greek keyboard `U`
Θ	`U+0398`	`Θ`	`Θ`	`Θ`	`\0398`	`\u0398`	`\Theta`	`Alt + 233`	Greek keyboard `Shift + U`
ϑ	`U+03D1`	`&thetasym;`	`ϑ`	`ϑ`	`\03D1`	`\u03D1`	`\vartheta`	`03D1` then `Alt + X` (Word)	Character Viewer
ϴ	`U+03F4`	`—`	`ϴ`	`ϴ`	`\03F4`	`\u03F4`	`—`	`03F4` then `Alt + X` (Word)	Character Viewer
∅	`U+2205`	`∅`	`∅`	`∅`	`\2205`	`\u2205`	`\emptyset`	`2205` then `Alt + X` (Word)	Character Viewer

Need the characters without any explanation? Open the Greek letters copy-paste sheet.

How to type the theta symbol

Windows

Fastest: press Win + . to open the emoji panel, choose the Symbols tab (Ω), then Greek.
Alt code: hold Alt and type 233 for Θ on the numeric keypad with Num Lock on.
Microsoft Word: type 03B8 and press Alt + X for θ; 0398 then Alt + X for Θ. Word converts it in place.

Mac

Add the Greek keyboard in System Settings → Keyboard → Input Sources, then U types θ and Shift + U types Θ.
Or open the Character Viewer with Ctrl + Cmd + Space and search “theta”.

iPhone and Android

iOS: Settings → General → Keyboard → Keyboards → Add New Keyboard → Greek. Tap the globe key to switch.
Android (Gboard): Settings → Languages → Add keyboard → Greek.
Or copy the character from the top of this page.

LaTeX

\theta — lowercase θ in math mode
\Theta — capital Θ
\vartheta — ϑ (greek theta symbol (script theta))
\emptyset — ∅ (empty set)

HTML, CSS and code

HTML: θ or θ or θ
CSS: content: "\03B8";
JavaScript / JSON: "\u03B8" — Python: "\u03b8"
In source code, prefer the escape over the pasted glyph — it survives every file encoding.

Full typing guide for every platform, including Linux and Google Docs → how to type Greek letters.

What does theta mean?

Mathematics

θ — an angle, and the angular coordinate in polar coordinates (r, θ)
Θ(n) — big-Theta, a tight bound in algorithm analysis

Statistics

θ — an unknown parameter to be estimated, with estimate θ̂

Physics

θ — angular displacement, and the Debye temperature θ_D
Θ — the dimension symbol for temperature

Finance & biology

theta — the time decay of an option
theta waves — 4–8 Hz brain waves

Theta at a glance

Position: 8th of 24
Uppercase / lowercase: Θ θ
Greek name: θήτα
Pronunciation: /ˈθiːtə/
Numeric value: 9
Became: Cyrillic Ѳ (fita)

Frequently asked questions

What is the theta symbol?

Theta (Θ θ) is the 8th letter of the Greek alphabet, pronounced /ˈθiːtə/ (“THAY-tuh or THEE-tuh”). It is most often used for angles, big-Theta notation, unknown parameters.

How do I type the theta symbol on a keyboard?

On Windows, press Win + . → Symbols → Greek, or in Microsoft Word type 03B8 and press Alt + X; the classic Alt code Alt + 233 types Θ. On a Mac, switch to the Greek keyboard and press U (Shift + U for the capital). Or simply copy it from the top of this page.

What is the LaTeX command for theta?

Use \theta for lowercase θ and \Theta for capital Θ, inside math mode: $\theta$ .

What is the Unicode and HTML code for theta?

Lowercase θ is U+03B8, written in HTML as θ or θ. Capital Θ is U+0398, written Θ or Θ.

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