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Diameter Symbol (⌀)
The diameter symbol (⌀) labels the width of a circle or a round part — a ⌀ 10 mm drill hole.
Diameter Symbol codes
| Code | Value |
|---|---|
| Unicode code point | U+2300 |
| Unicode name | Diameter Sign |
| HTML named entity | None — use the decimal or hex code below |
| HTML decimal | ⌀ |
| HTML hex | ⌀ |
| CSS content code | \2300 |
| JavaScript / JSON | \u2300 |
| Windows Alt code | No standard Alt code — copy it from the card above |
Diameter Symbol variants (4)
4 related glyphs — click any tile to copy it. Tiles with a page open that symbol's own page.
Meaning & usage
⌀ is a circle with a slash, drawn to label diameters on engineering drawings, pipe sizes, drill specs and camera lens filters (⌀ 58 mm). It is one of the most confused symbols in Unicode: it is not the Danish/Norwegian letter Ø, not the empty-set symbol ∅ of maths, and not zero. On drawings, ⌀ always means 'the diameter is…' — using the wrong lookalike can confuse both search and screen readers, so copy the genuine ⌀ here.
Examples in use
- Drill a ⌀ 6 mm hole
- Lens filter size ⌀ 67 mm
- Pipe: ⌀ 110 mm PVC
How to type the diameter symbol
Windows
There is no Alt code or direct key for ⌀. In Microsoft Word, type 2300 and press Alt+X to convert it. Everywhere else, click the Copy button at the top of this page and paste it (Ctrl+V) — that always works.
Mac
There is no Option-key shortcut for ⌀ on a Mac. Open the Character Viewer with Control+Command+Space, search for "Diameter Symbol", and double-click to insert — or copy it from this page.
iPhone & Android
Most phone keyboards have no built-in key for ⌀. Open this page on your phone, tap Copy, then paste it into your message or bio. (On Android, Gboard's emoji search finds some symbols by name.)
Linux
Press Ctrl+Shift+U, type 2300 and press Enter (works in most GTK apps and terminals with IBus). Or copy it from this page.
Frequently asked questions
Is ⌀ the same as Ø?
No. Ø is a letter in Danish and Norwegian alphabets. ⌀ (U+2300) is the diameter sign used in technical drawings. They look alike but mean completely different things to computers.
How do I type the diameter symbol?
There is no standard keyboard shortcut or Alt code. Copy ⌀ from this page; CAD and drawing tools often insert it from their text-symbol menus.
Why does ⌀ sometimes show as a box or question mark?
The box (called tofu) means the device or font viewing it has no drawing for U+2300 (Diameter Sign). The character itself is fine — try a different font or a newer device, or use one of the variants on this page.
Is the Diameter Symbol free to use?
Yes. ⌀ is a standard Unicode text character published in the Unicode Character Database. You may use it in personal and commercial documents, designs and products without permission or payment.
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Data: Unicode Character Database · Page updated 2026-11-13