Diameter Symbol (⌀): How to Type It on Any Keyboard (Windows, Mac, Word, Excel, Google Docs + Phone)

The diameter symbol looks like this: ⌀. It’s used in engineering, machining, technical drawings, and CAD to mean “diameter” — the distance straight across a circle through its center.

In this guide, you’ll learn all the reliable ways to type the diameter symbol on Windows, Mac, Microsoft Word, Excel, PowerPoint, Google Docs, and mobile. I’ll also show you a common look-alike symbol people confuse with it, so you don’t use the wrong one.

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Quick copy (fastest way)

This method is perfect when you just want the symbol immediately. You copy the character and paste it anywhere (documents, emails, WhatsApp, spreadsheets, etc.).

Paste:

• Windows: Ctrl + V
• Mac: Command + V
• Phone: tap and hold → Paste

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What does the diameter symbol mean?

Before typing it, it helps to know what it’s communicating.

When you see something like:

• ⌀10 mm
• ⌀ 25
• ⌀0.5 in

It means the circle/hole/pipe has a diameter of 10 mm, 25, or 0.5 inches.

Diameter is the straight line across a circle, passing through the center (not the edge-to-center distance — that one is radius).

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Diameter symbol vs “O with a slash” (⌀ vs Ø) — important difference

A lot of people search “diameter symbol” and end up typing the wrong thing because two characters look similar:

• ⌀ = Diameter symbol (this is what technical drawings often want)
• Ø = Latin capital letter O with stroke (a letter used in some languages)

They can look almost the same, so some drawings (especially older ones) use Ø as a practical substitute when ⌀ isn’t available. But if you want to be accurate, try to use ⌀ when possible.

Quick comparison:

• True diameter symbol: ⌀
• Common substitute/look-alike: Ø

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Method 1: Type the diameter symbol in Microsoft Word using “Alt + X” (best Word method)

This is one of the easiest and most reliable methods if you’re using Microsoft Word, especially on a laptop (no numeric keypad needed).

It works because Word can convert a Unicode code into a symbol. You type the Unicode and press Alt + X, and Word turns it into the symbol.

Steps (Word for Windows)

1. Click where you want to insert the symbol.
2. Type this code: 2300
3. Press Alt + X
4. Word converts it to: ⌀

Why beginners like this method: you don’t need to search menus or remember complicated key combos—just the code 2300.

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Method 2: Insert the diameter symbol in Word using the Symbol menu (no codes needed)

If you don’t want to memorize codes, Word has a built-in symbol library where you can “pick” the diameter symbol from a list.

Steps (Word on Windows or Mac)

1. Click where you want the symbol.
2. Go to Insert → Symbol → More Symbols
3. Look for ⌀
4. Click Insert

Tip: After you insert it once, Word often shows it in the “recently used symbols” list, so next time it takes just a few seconds.

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Method 3: Type the diameter symbol on Mac (Character Viewer method)

Mac doesn’t rely on Alt codes like Windows. Instead, the most reliable way to insert symbols is through Character Viewer, a built-in panel where you can search for symbols by name.

Steps (Mac)

1. Click where you want the symbol.
2. Press Control + Command + Space (this opens Character Viewer).
3. Search for diameter
4. Click ⌀ to insert it.

If you can’t find it by search: try searching:

• circle slash
• empty set
• slash circle

(Some Macs label symbols differently depending on the keyboard and macOS version.)

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Method 4: Insert the diameter symbol in Excel (Windows or Mac)

Excel is great for specs, part lists, and measurements. The easiest way in Excel is usually Insert → Symbol or simply copy/paste.

Option A: Copy and paste (fastest)

Copy ⌀ from this page and paste into your cell.

Option B: Insert Symbol

1. Click the cell where you want the symbol.
2. Go to Insert → Symbol
3. Find ⌀
4. Click Insert

Beginner tip: If you don’t see ⌀, try changing the font in the Symbol window (some fonts show more symbols than others).

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Method 5: Insert the diameter symbol in PowerPoint

In PowerPoint, you’ll usually insert ⌀ the same way you do in Word and Excel: through the symbol menu or by copy/paste.

Steps

1. Click inside your text box.
2. Go to Insert → Symbol
3. Find ⌀
4. Click Insert

Or just copy ⌀ and paste it into your slide.

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Method 6: Type the diameter symbol in Google Docs (Special Characters)

Google Docs has a built-in tool that lets you insert special symbols by searching their names. This is perfect if you’re working in the browser and don’t want to install anything.

Steps (Google Docs)

1. Click where you want the symbol.
2. Go to Insert → Special characters
3. Search for diameter
4. Click ⌀ to insert

If search doesn’t work: draw a circle with a slash in the “draw symbol here” box, or try searching:

• circle slash
• empty set

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Method 7: Windows Character Map (reliable backup for any Windows app)

If you’re on Windows and a shortcut isn’t working, Character Map is a reliable “find and copy” tool built into Windows. It’s especially helpful for apps that don’t support special keyboard shortcuts.

Steps (Windows)

1. Click Start and search Character Map
2. Open it
3. Find ⌀ (you may need to scroll)
4. Click Select → Copy
5. Paste it where you need

Tip: If you can’t find ⌀, switch the font inside Character Map (some fonts don’t include every symbol).

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Method 8: iPhone and Android (easiest way)

Most phone keyboards don’t include the diameter symbol as a standard key. That’s why the simplest method is copy/paste.

Best method: Copy and paste

Copy: ⌀
Paste into any app.

Pro tip (iPhone): set a shortcut

If you type it often:

1. Settings → General → Keyboard → Text Replacement
2. Shortcut: dia
3. Phrase: ⌀

Now typing dia can suggest ⌀ instantly.

Pro tip (Android)

Many keyboards (like Gboard) allow personal dictionary shortcuts. Add dia → ⌀ so it appears as a suggestion.

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Diameter symbol codes (Unicode + HTML)

If you’re writing a blog post, editing a website, or working with HTML, you might need the code version of the symbol.

• Symbol: ⌀
• Unicode: U+2300
• HTML (decimal): ⌀
• HTML (hex): ⌀

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Common problems (and quick fixes)

“I typed something and got Ø instead of ⌀”

That happens a lot. Ø is a letter; ⌀ is the diameter symbol.
Fix: Use Word Alt + X (2300), Insert Symbol, or copy/paste ⌀.

“I can’t find ⌀ in the Symbol menu”

Some fonts don’t show all symbols.
Fix: In the Symbol window, change the font to something common like:

• Arial
• Calibri
• Segoe UI Symbol
• Times New Roman

“Google Docs search doesn’t show diameter”

Try searching circle slash or draw the symbol in the “draw” box.

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Best method summary (easy to remember)

If you only want one method per platform:

• Word (Windows): type 2300 → press Alt + X
• Windows (any app): copy/paste ⌀ or use Character Map
• Mac: Control + Command + Space → search “diameter”
• Google Docs: Insert → Special characters → search “diameter”
• Phone: copy/paste (or set text replacement)