What is the Unicode code point for the diameter symbol?

The diameter sign is U+2300, used in engineering and machining to mark the diameter of a hole, shaft, or circular part.

What is the HTML entity for the diameter symbol?

There is no named HTML entity for the diameter sign. Use the numeric entity ⌀ and it will render as ⌀.

How do I type the diameter symbol in LaTeX?

Load the wasysym package and use \diameter, for example $\diameter 12\text{mm}$. The gensymb package alternative is \diameter as well, but wasysym is the more common source.

How do I type the diameter symbol on a Mac?

Open the Character Viewer with Control+Command+Space, search "diameter sign", then double-click the symbol to insert it. There is no direct Option key shortcut for this character.

How do I type the diameter symbol on Windows?

In Microsoft Word, type 2300 then press Alt+X to convert it to ⌀. Outside Word, use the Character Map app or copy the symbol from a page like this one.

Is the diameter symbol the same as the empty set symbol?

No. The diameter sign (⌀, U+2300) is a circle with a diagonal slash from lower-left to upper-right, used in engineering. The empty set symbol (∅, U+2205) looks similar but is a math character for "a set with no elements" and its slash angle and circle proportions differ slightly by font. Use ⌀ for measurements and ∅ for set theory.

Is the diameter symbol the same as the Greek letter phi?

No. The Greek letter phi (φ, U+03C6, or Φ, U+03A6) is a letter used in math, physics, and the Greek alphabet. The diameter sign (⌀) is unrelated to the Greek alphabet even though some fonts render them similarly; mixing them up in a drawing can be read as the wrong dimension by a machinist.

Diameter Symbol

Name: Diameter Symbol
Availability: InStock
Author: Nham Vu

Copy the diameter symbol (⌀) and find the exact Unicode value, HTML entity, LaTeX command, or keyboard shortcut for your platform.

Diameter Symbol

Click the symbol to copy it

Formats

Character ⌀

Unicode U+2300

HTML decimal ⌀

HTML hex ⌀

LaTeX \diameter

CSS escape \2300

JS / JSON escape ⌀

Click any row to copy that exact string.

Keyboard Shortcuts

System	Shortcut	Notes
Windows (Word)		Type 2300 then press Alt+X to convert it.
Windows (general)		No plain Alt code exists; use Character Map or copy the symbol above.
Mac		Opens Character Viewer; search "diameter sign" and double-click to insert.
Linux (GTK)		Type the hex code, then press Enter or Space.
LaTeX		Requires the wasysym package, for example $\diameter 12\text{mm}$.

Try it

Enter a measurement to build a ready-to-paste diameter callout.

⌀

⌀12 mm

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Summary

Copy the diameter symbol (⌀) and find the exact Unicode value, HTML entity, LaTeX command, or keyboard shortcut for your platform.

How it works

Click the large diameter symbol to copy it to your clipboard.
Or click any format in the list (Unicode, HTML entity, LaTeX, CSS escape) to copy that exact string.
Use the shortcut table to type the symbol directly from your keyboard on Windows, Mac, or Linux.
Paste the symbol anywhere: CAD drawings, spreadsheets, documents, or chat.

Use cases

Label a hole or shaft size on a mechanical drawing, such as ⌀12 mm.
Insert the diameter symbol into a LaTeX document with \diameter from the wasysym package.
Write a bolt or pipe callout in a spec sheet without typing out the word "diameter".
Add the diameter symbol to CAD software, CNC programs, or engineering notes.
Learn the keyboard shortcut so you never need to look it up again.
Copy the correct HTML entity for a web page instead of pasting a raw Unicode character.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu