Math symbol reference

Pi π

The constant equal to a circle’s circumference divided by its diameter.

π
UnicodeU+03C0
LaTeX\pi
HTML entityπ
HTML decimalπ
MathML<mi>π</mi>

Semantic identity and intent

Semantic type

constant

A named mathematical constant or fixed symbolic quantity.

Primary search task

identify the constant, understand its role, and copy the correct notation

Mathematical ConstantsGreek LettersGeometry Symbols

MathML token

<mi>

Treat π as a named mathematical constant only when the surrounding field defines that convention. The same glyph can be an ordinary variable in another context, so preserve the local definition.

Characters to distinguish

  • ° — Degree Sign
  • e — Euler’s Number

Use π in the right format

Meaning and usage

The constant equal to a circle’s circumference divided by its diameter.

Used in geometry, trigonometry, analysis, probability, and many scientific formulas.

Pronunciation: pi

Formula examples

C=2\pi r
A=\pi r^2

How to type Pi

Windows
Use Character Map or enter U+03C0 in a Unicode-aware app.
macOS
Open Character Viewer with Control–Command–Space and search by name.
Microsoft Word
Type \pi in an equation and press Space.
iPhone and iPad
Copy and paste π, or use a math/LaTeX app. The standard iOS keyboard may not expose every mathematical symbol.
Android
Copy and paste π, or use a math keyboard or LaTeX editor. Keyboard layouts vary by device and app.
Google Docs
For plain text, paste π or use Insert → Special characters. For structured math, use the equation editor and verify \pi.
Excel
Paste π into a cell or use Insert → Symbol when available. Ordinary cells preserve the character but do not interpret LaTeX commands.

Common mistakes

  • Do not substitute a visually similar Latin or differently styled character for π; case and mathematical alphabet style can identify different quantities.
  • For plain text, copy π as U+03C0; for structured equations, use \pi in math mode. A look-alike glyph or image can break search, accessibility, or parsing when the intended character is Pi.

When to use π

  • Use π in plain text when a Unicode character is appropriate and the destination preserves U+03C0.
  • Use \pi in an equation editor when mathematical spacing or structure matters.
  • Define the local meaning when Pi is used in constants, greek, geometry with a field-specific convention.

Look-alikes and related characters

  • ° — Degree Sign
  • e — Euler’s Number

Font and compatibility notes

Glyph shape can vary by font. Verify the code point after copying, and prefer LaTeX or MathML for structured equations.

Continue the workflow

From Pi to a finished equation

  1. Copy the characterUse π in plain text when Unicode is accepted.
  2. Choose a structured formatUse \pi for LaTeX or the MathML snippet for accessible web equations.
  3. Edit or convertOpen the value in the editor or converter without retyping it.

Review and source notes

Quality tier: core

Last reviewed: 2026-07-26

Review method: Checked Pi against its Unicode identity, LaTeX representation, HTML serialization, MathML token, and copy-and-paste behavior.

Verified against: Unicode Standard, Unicode mathematical notation guidance, and established LaTeX/MathML syntax.

Reference sources

Frequently asked questions

What does the Pi symbol mean?

The constant equal to a circle’s circumference divided by its diameter.

What is the LaTeX command for π?

Use \pi in a compatible math environment.

Can I copy π as Unicode?

Yes. Use the copy button above to copy the Unicode character directly.

Reuse, attribution, and correction

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Copy a citation, permanent link, Markdown link, or self-contained embed card. Each reusable format points readers back to the maintained canonical page.

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