Diameter Symbol Copy and Paste (⌀ Ø ø)
Diameter sign (proper)
Unicode U+2300 · HTML ⌀
Tap any symbol to copy it. Each tap also adds it to the box above, so you can copy several together.
Codes for every symbol on this page (Unicode, HTML, Alt, Mac, Word)
| Symbol | Name | Unicode | HTML | Windows Alt code | Mac | MS Word |
|---|---|---|---|---|---|---|
| ⌀ | Diameter sign (proper) | U+2300 | ⌀ | - | - | 2300 then Alt+X |
| Ø | Capital O with stroke | U+00D8 | Ø | Alt+0216 | Option+Shift+O | 00D8 then Alt+X |
| ø | Small o with stroke | U+00F8 | ø | Alt+0248 | Option+O | 00F8 then Alt+X |
| ∅ | Empty set (not diameter) | U+2205 | ∅ | - | - | 2205 then Alt+X |
The diameter symbol ⌀ is a circle with a slanting line through it, written before a size to show it is a diameter: ⌀20 mm means a round part 20 mm across. Engineers, machinists and civil site teams use this dia symbol on drawings, bar schedules and purchase lists every day.
Many people type the letter Ø instead because it has an easy Alt code. Both are in the grid above, so tap the one you need. Below you will find the dia symbol shortcut for every app.
Diameter Symbol Shortcut: All Methods at a Glance
| Where | ⌀ (true diameter sign) | Ø (common substitute) |
|---|---|---|
| Windows keyboard | no Alt code | Alt+0216 |
| Microsoft Word | 2300 then Alt+X | 00D8 then Alt+X or Alt+0216 |
| Excel | =UNICHAR(8960) or Insert > Symbol | Alt+0216 or =CHAR(216) |
| Mac | Character Viewer (Control+Command+Space) | Option+Shift+O |
| AutoCAD text | %%c | %%c |
| Google Docs | Insert > Special characters, search "diameter" | search "O with stroke" |
| Phone | copy from this page | long-press O on many keyboards |
| HTML | ⌀ | Ø |
Small ø is Alt+0248 on Windows and Option+O on a Mac. It is used in Danish and Norwegian words, and some people use it for diameter in handwritten-style notes.
Diameter Symbol in Keyboard: Windows Shortcut
You will not find a dia symbol in keyboard layouts as a printed key. The quickest diameter symbol keyboard shortcut on Windows is the Alt code for Ø:
- Turn on Num Lock.
- Hold the Alt key.
- Type 0216 on the number pad on the right side.
- Release Alt. Ø appears.
This dia symbol keyboard shortcut works in Word, Excel, Notepad, browsers and most other programs. On a laptop without a number pad, use Windows+. to open the symbol panel, or copy the symbol from this page. The true ⌀ (U+2300) has no Alt code at all, which is why the Ø letter became so common as a substitute.
Diameter Symbol in Excel
Bills of quantities, pipe lists and rebar schedules are often made in Excel, so the dia symbol in Excel is a common need. Here are four ways:
- Alt code shortcut: click the cell, hold Alt, type 0216 on the number pad. This is the usual dia symbol in Excel shortcut and gives Ø.
- Formula for Ø: =CHAR(216). To build a label from a number in A2: =CHAR(216)&A2&" mm" gives Ø25 mm.
- Formula for the true ⌀: =UNICHAR(8960). 8960 is the decimal form of the code 2300.
- Number format (best for calculations): select the cells, press Ctrl+1, choose Custom and type
"Ø"0" mm". A cell holding 25 then shows Ø25 mm but stays a number, so you can still add, sort and multiply.
Insert > Symbol also works in Excel: choose the font Segoe UI Symbol or Cambria Math and look in the Miscellaneous Technical subset for ⌀.
Dia Symbol in Word and AutoCAD
Word
- Type 2300 then press Alt+X for ⌀.
- Or press Alt+0216 for Ø.
- Or Insert > Symbol > More Symbols, font Segoe UI Symbol, subset Miscellaneous Technical.
- If you use it daily, set an AutoCorrect entry (File > Options > Proofing > AutoCorrect Options), for example replace
dia1with ⌀.
AutoCAD
In single-line and multiline text, typing %%c gives the diameter symbol, so %%c50 shows ⌀50. Dimensions on round features usually add it automatically. Other AutoCAD codes like %%d (degree) and %%p (plus-minus) follow the same idea; see the degree symbol and plus-minus symbol pages for their text forms.
⌀ vs Ø vs ∅: Which One Is Correct?
| Character | Name | Proper use |
|---|---|---|
| ⌀ | Diameter sign (U+2300) | diameter in engineering and technical drawings |
| Ø ø | Latin letter O with stroke | a letter in Danish and Norwegian; widely used as a diameter substitute |
| ∅ | Empty set (U+2205) | maths: a set with no elements |
The symbol of diameter in standards and CAD fonts is ⌀. It is usually a perfect circle with the line at about 45° and sits at the same height as the numbers. Ø is a letter, so in some fonts it looks narrower. For most site notes and Excel sheets Ø is accepted. Avoid ∅ for diameter: it belongs to set theory on our math symbols page.
Examples of the Diameter Symbol in Use
- Civil work: 12 nos. ⌀16 mm TMT bars @ 150 mm c/c.
- Plumbing: ⌀110 mm PVC pipe, ⌀25 mm CPVC line.
- Mechanical drawing: ⌀30 H7 hole, ⌀8 thru 4 holes.
- Cooking or crafts: ⌀20 cm cake tin.
In a GD&T feature control frame, ⌀ before the tolerance value means the tolerance zone is a cylinder, for example position ⌀0.1. Learn more on the GD&T symbols page, and for drawing angles see the angle symbol guide.
Frequently asked questions
What is the diameter symbol shortcut key?
On Windows the usual dia symbol shortcut key is Alt+0216, which types Ø. In Word, 2300 followed by Alt+X gives the true diameter sign ⌀. On a Mac, Option+Shift+O gives Ø.
How do I type the dia symbol in Excel?
Hold Alt and type 0216 on the number pad, or use the formula =CHAR(216). For the proper ⌀ sign use =UNICHAR(8960).
What does %%c mean in AutoCAD?
%%c is a text code that AutoCAD shows as the diameter symbol. Typing %%c25 in a text object displays ⌀25.
Is the diameter symbol the same as the empty set symbol?
No. They look alike, but ⌀ is for diameter and ∅ is the maths symbol for an empty set. Each has its own code.
How do I type the diameter symbol on keyboard of a phone?
On many Android and iPhone keyboards, long-press the O key and pick Ø from the pop-up. For the true ⌀ sign, copy it from this page.