Ο
Phi in Mathematics
In Mathematics, the Phi symbol (Ο) is commonly used. Learn how to copy and use it in your technical documents.
Unicode
U+03C6
HTML Entity
φ
LaTeX Sequence
\phi
Primary Field
MathematicsMathematics Application
Phi represents the golden ratio (β1.618), magnetic flux in electromagnetism, phase angle in waves and AC circuits, electric potential, and Euler’s totient function in number theory.
How to type Phi (Ο)
- Fastest: click Ο 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 AltβX 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
What is the golden ratio Ο?
An irrational number β1.618 that appears in art, architecture and nature, where a+b is to a as a is to b.
What is magnetic flux Ξ¦?
A measure of the magnetic field passing through a surface, central to Faraday’s law of induction.
Write mathematical and scientific expressions
Need to pair this symbol with other operators?