Theta Symbol Copy and Paste (θ Θ ϑ)
Small theta
Unicode U+03B8 · HTML θ
Tap any symbol to copy it. Each tap also adds it to the box above, so you can copy several together.
Codes for every symbol on this page (Unicode, HTML, Alt, Mac, Word)
| Symbol | Name | Unicode | HTML | Windows Alt code | Mac | MS Word |
|---|---|---|---|---|---|---|
| θ | Small theta | U+03B8 | θ | - | - | 03B8 then Alt+X |
| Θ | Capital theta | U+0398 | Θ | Alt+233 | - | 0398 then Alt+X |
| ϑ | Script theta | U+03D1 | ϑ | - | - | 03D1 then Alt+X |
| ѳ | Cyrillic fita | U+0473 | ѳ | - | - | 0473 then Alt+X |
The theta symbol θ is the Greek letter that almost every trigonometry question starts with: "If sin θ = 3/5, find cos θ." It is the eighth letter of the Greek alphabet and is said like the "th" in "thin" (not the "th" in "this").
Tap θ in the grid for an instant theta symbol copy paste. Capital Θ, the curly script form ϑ and a historic Cyrillic letter ѳ are there too. Since θ is hard to find on most keyboards, the typing guide below covers laptops, Word and mobile keyboards one by one.
Theta Symbol in Maths: Sin θ, Cos θ and Tan θ
In trigonometry, θ is simply the name given to an unknown angle. With a right triangle and angle θ:
| Ratio | Formula | Value at θ = 30° |
|---|---|---|
| sin θ | opposite ÷ hypotenuse | 1/2 |
| cos θ | adjacent ÷ hypotenuse | √3/2 |
| tan θ | opposite ÷ adjacent | 1/√3 |
The most used identity is sin²θ + cos²θ = 1. So if sin θ = 3/5, then cos θ = 4/5 (in the first quadrant). When you type answers, write the sin theta symbol and cos theta symbol as "sin θ" and "cos θ" with a space, which looks neat in Word and Google Docs.
Angles can be in degrees or radians: θ = 90° is the same as θ = π/2. The degree symbol and pi symbol pages cover both units, and the angle symbol ∠ is useful for naming angles in geometry.
θ Beyond Trigonometry
- Polar coordinates: a point is written (r, θ), where r is the distance from the origin and θ is the angle from the x-axis.
- Physics: θ is the angle of projection, the angle of an inclined plane, and angular displacement. Some physics books also use θ for temperature.
- Computer science: capital Θ is used in "Big Theta" notation, as in Θ(n log n), to describe how an algorithm's running time grows.
- Script form ϑ: a curly theta some authors use when θ already has another job.
- ѳ (fita): an old Cyrillic letter that came from Greek theta. It is not used in maths.
How to Type the Theta Symbol on Keyboard and in Word
Windows laptop or desktop
Capital Θ: hold Alt and type 233 on the number keypad (Num Lock on). Small θ has no standard Alt code. Use one of these instead:
Theta symbol in Word
- Type
03B8. - Press Alt+X right away; the code becomes θ.
Inside an equation (Insert > Equation or Alt+=), type \theta and press Space. Avoid the old trick of typing q in Symbol font: it looks like θ, but if you copy it into another app it turns back into q.
Mac
There is no Option key for θ. Open the Character Viewer with Control+Command+Space and search "theta".
Google Docs and Excel
Docs: Insert > Special characters, search "theta", or \theta in an equation. Excel: =UNICHAR(952) or Insert > Symbol.
Theta Symbol in Mobile Keyboard
Gboard, Samsung Keyboard and the iPhone keyboard do not show θ on their usual ?123 or #+= pages. You have two easy options:
- Copy once, reuse: copy θ from this page. In Gboard you can pin it in the clipboard, so it stays ready for your whole homework session.
- Add a Greek keyboard: in Gboard go to Settings, Languages, Add keyboard, Greek. On iPhone open Settings, General, Keyboard, Keyboards, Add New Keyboard, Greek. Switch with the globe key; on the Greek layout, θ usually sits where English u is, but check your own layout.
See the Greek letters page for other angle letters like α, β and φ.
Frequently asked questions
What is the symbol of theta?
Small theta is θ and capital theta is Θ. Trigonometry and physics use the small form for angles.
How do I type the theta symbol in keyboard shortcuts on Windows?
Alt+233 on the number pad gives capital Θ. For small θ, type 03B8 and press Alt+X in Word, or copy it from this page.
Why is θ used for angles?
It is a long-standing convention in maths books, along with α, β and φ. Using Greek letters for angles keeps them separate from side lengths, which are usually English letters like a, b and c.
Is θ the same as the number zero with a line?
No. θ is a Greek letter with a horizontal bar inside an oval. A slashed zero (0 with a diagonal line) is just a way of writing zero clearly, and the empty set sign ∅ is different again.
Can I use θ in a WhatsApp message?
Yes. θ is standard Unicode text, so it displays on all modern phones. Copy it from the grid and paste it into the chat.