HTML Entity for Squared Minus (⊟)

Beginner
⏱️ 5 min read
📚 Updated: Jun 2026
🎯 1 Code Example
Unicode U+229F

What You'll Learn

How to display the Squared Minus (⊟) in HTML using named, hexadecimal, decimal, and CSS escape methods. This character is U+229F (SQUARED MINUS) in the Mathematical Operators block (U+2200–U+22FF)—a boxed minus sign used in mathematical notation.

Render it with ⊟, ⊟, ⊟, or CSS \229F. For complex formulas, consider MathML or LaTeX renderers; for inline operator symbols, HTML entities work well.

⚡ Quick Reference — Squared Minus

Unicode U+229F

Mathematical Operators

Hex Code ⊟

Hexadecimal reference

HTML Code ⊟

Decimal reference

Named Entity ⊟

Most readable option

Reference Table
Name           Value
────────────   ──────────
Unicode        U+229F
Hex code       ⊟
HTML code      ⊟
Named entity   ⊟
CSS code       \229F
Meaning        Squared minus
Block          Mathematical Operators (U+2200–U+22FF)
1

Complete HTML Example

A simple example showing ⊟ using the named entity, hexadecimal code, decimal HTML code, and a CSS content escape:

html
<!DOCTYPE html>
<html>
<head>
 <style>
  #point::after{
   content: "\229F";
  }
 </style>
</head>
<body>
<p>Squared minus (named): &minusb;</p>
<p>Squared minus (hex): &#x229F;</p>
<p>Squared minus (decimal): &#8863;</p>
<p id="point">Squared minus (CSS): </p>
</body>
</html>
Try it Yourself

🌐 Browser Support

Squared Minus (⊟) is supported in all modern browsers when fonts include Mathematical Operators glyphs:

Chrome1+
Firefox1+
Safari1+
Edge12+
Opera4+
Android4.4+
iOS Safari1+

👀 Live Preview

See the squared minus operator in mathematical contexts:

Single symbol
Named entity &minusb; renders as ⊟
In notation A ⊟ B
Related operator ⊟ (minus)  |  ⊞ (plus, &plusb;)
Numeric refs &minusb; &#x229F; &#8863; \229F

🧠 How It Works

1

Named HTML Entity

&minusb; is the semantic named entity for the squared minus operator—the most readable option in source HTML.

HTML markup
2

Hexadecimal Code

&#x229F; uses Unicode hexadecimal 229F to display ⊟ in HTML markup.

HTML markup
3

Decimal HTML Code

&#8863; uses decimal Unicode value 8863 for the same character.

HTML markup
4

CSS Entity

\229F is used in CSS stylesheets in the content property of pseudo-elements like ::after.

CSS stylesheet
=

Same visual result

All four methods produce . Unicode U+229F in Mathematical Operators (U+2200–U+22FF).

Use Cases

Squared Minus (⊟) commonly appears in:

📐 Mathematical notation

Equations and formulas using boxed minus operators.

📄 Technical documentation

API references and developer guides with math operator notation.

📚 Academic papers

Research documents and scholarly publications on mathematical concepts.

🏫 Educational content

Tutorials and instructional materials about mathematical operators.

🔬 Scientific publications

Technical reports requiring precise mathematical notation.

🛠 Formula editors

Web-based math tools and interactive learning applications.

💡 Best Practices

Do

  • Use &minusb; for readable source markup
  • Provide context when using ⊟ in mathematical expressions
  • Use MathML or dedicated math renderers for complex nested formulas
  • Pick one entity style (named, hex, or decimal) per project
  • Test rendering with math-friendly fonts

Don’t

  • Use padded Unicode notation like U+0229F—the correct value is U+229F
  • Use CSS \0229F with a leading zero—prefer \229F
  • Confuse ⊟ with regular minus − (&minus;) or hyphen-minus -
  • Expect HTML entities alone to handle full equation layout
  • Put CSS escape \229F in HTML text nodes

Key Takeaways

1

Four HTML/CSS references all render ⊟

&minusb; &#x229F; &#8863;
2

For CSS stylesheets, use \229F in the content property

3

Unicode U+229F — SQUARED MINUS (⊟)

4

&minusb; is the standard named entity for this operator

❓ Frequently Asked Questions

Use &minusb; (named), &#x229F; (hex), &#8863; (decimal), or \229F in CSS content. All four render ⊟.
U+229F (SQUARED MINUS). Mathematical Operators (U+2200–U+22FF). Hex 229F, decimal 8863, named &minusb;.
For mathematical notation, technical documentation, academic papers, educational content, scientific publications, and any content requiring precise mathematical operator representation.
The named entity &minusb; is more readable and easier to remember. Numeric codes (&#8863; or &#x229F;) are explicit and work in all contexts. Both produce ⊟; prefer the named entity for readability.
HTML references (&minusb;, &#8863;, or &#x229F;) go in markup. The CSS escape \229F is used in stylesheets, typically in the content property of ::before or ::after. Same visual result, different layers of the stack.

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About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

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