Home / Mathematics / Symbols / Theta
θ

Theta in Mathematics

In Mathematics, the Theta symbol (θ) is commonly used. Learn how to copy and use it in your technical documents.

Unicode

U+03B8

HTML Entity

θ

LaTeX Sequence

\theta

Primary Field

Mathematics

Mathematics Application

Theta is the go‑to symbol for an angle, especially in trigonometry and polar coordinates, where a point is written (r, θ). It also appears as a plane‑angle measure and, in options trading, as the rate of time decay.

How to type Theta (θ)

  • Fastest: click θ on the keyboard above — it copies to your clipboard, ready to paste into Word, Google Docs, email or a forum.
  • Unicode: the code point is shown in the panel above; on Windows you can also use Alt‑X after the hex code in Word.
  • LaTeX: use the command shown above inside math mode.
  • Anywhere: because it’s standard Unicode, it keeps its exact form across apps and devices.

Frequently asked questions

Why is θ used for angles?

By long convention θ (and φ) label unknown angles in trigonometry, physics and engineering diagrams.

What is θ in polar coordinates?

The angle measured from the positive x‑axis to the point, paired with the radius r.

Write mathematical and scientific expressions

Need to pair this symbol with other operators?

Open Full Keyboard