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)