HTML Entity for Plus Minus (±)

Beginner
⏱️ 5 min read
📚 Updated: Jun 2026
🎯 1 Code Example
Unicode U+00B1
HTML Entity for plus-minus sign tutorial illustration

What You'll Learn

How to display the plus-minus sign (±) in HTML using various entity methods. The plus-minus symbol indicates a value that may be positive or negative—common in tolerances, measurement uncertainty, quadratic roots, and scientific notation.

This character is part of the Latin-1 Supplement Unicode block and can be rendered with a hexadecimal reference, a decimal reference, the named entity ±, or a CSS escape in the content property. Do not confuse ± with ordinary + (U+002B) or the mathematical minus sign − (U+2212).

⚡ Quick Reference — Plus Minus Entity

Unicode U+00B1

Latin-1 Supplement block

Hex Code ±

Hexadecimal reference

HTML Code ±

Decimal reference

Named Entity ±

Most readable option

Reference Table
Name           Value
────────────   ──────────
Unicode        U+00B1
Hex code       ±
HTML code      ±
Named entity   ±
CSS code       \B1
Meaning        Plus-minus sign
Related        U+002B = plus sign (+)
               U+2212 = minus sign (−)
               U+2213 = minus-or-plus sign (∓)
Block          Latin-1 Supplement (U+0080–U+00FF)
1

Complete HTML Example

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

html
<!DOCTYPE html>
<html>
<head>
 <style>
  #point::after{
   content: "\B1";
  }
 </style>
</head>
<body>
<p>Plus-minus (hex): &#xB1;</p>
<p>Plus-minus (decimal): &#177;</p>
<p>Plus-minus (named): &plusmn;</p>
<p id="point">Plus-minus (CSS): </p>
</body>
</html>
Try it Yourself

🌐 Browser Support

The plus-minus entity is universally supported in all modern browsers:

Chrome 1+
Firefox 1+
Safari 1+
Edge 12+
Opera 4+
Android 4.4+
iOS Safari 1+

👀 Live Preview

See the plus-minus sign rendered live in different contexts:

Tolerance Length: 10 mm ± 0.5 mm
Large glyph ±
Quadratic roots x = −1 ± √5
Not the same as Plus +  |  Minus −  |  Minus-or-plus ∓
Entity refs &#xB1; &#177; &plusmn; \B1

🧠 How It Works

1

Hexadecimal Code

&#xB1; uses the Unicode hexadecimal value B1 to display the plus-minus sign. The x prefix indicates hexadecimal format.

HTML markup
2

Decimal HTML Code

&#177; uses the decimal Unicode value 177 to display the same character. This is one of the most commonly used methods.

HTML markup
3

CSS Entity

\B1 is used in CSS stylesheets, particularly in the content property of pseudo-elements like ::before and ::after.

CSS stylesheet
4

Named Entity

&plusmn; is the semantic named entity — the easiest to read in source HTML and the most self-descriptive option.

HTML markup
=

Same visual result

All four methods produce the plus-minus glyph: ±. Unicode U+00B1 sits in the Latin-1 Supplement block (U+0080–U+00FF).

✅

Use Cases

The plus-minus sign (±) commonly appears in the following scenarios:

📐 Tolerances

Manufacturing specs: 100 mm ± 2 mm, fit and finish dimensions.

🔬 Science & Lab

Measurement uncertainty and error bars in experimental results.

📄 Math Formulas

Quadratic solutions, square roots, and dual-outcome equations.

🌡 Ranges

Temperature, voltage, or weight ranges expressed as center ± delta.

💻 Engineering Docs

CAD notes, datasheets, and technical specifications on the web.

🎓 Education

Algebra, physics, and statistics courses teaching uncertainty notation.

♿ Accessibility

Pair ± with spoken “plus or minus” in screen-reader-friendly content.

💡 Best Practices

Do

  • Use &plusmn; for readable tolerance and science markup
  • Pick one style (hex / decimal / named) per project
  • Use proper spacing: 10 ± 2 not 10±2
  • Distinguish ± from + and from mathematical −
  • Test rendering across browsers and fonts used in technical docs

Don’t

  • Confuse ± (U+00B1) with + (U+002B) or − (U+2212)
  • Use +/- when the proper ± symbol is intended
  • Use CSS escape \B1 inside HTML text nodes
  • Use HTML entities in JS (use \u00B1 instead)
  • Mix ± and ∓ (−/+) without understanding the difference

Key Takeaways

1

Three HTML references all render ±

&#xB1; &#177; &plusmn;
2

For CSS stylesheets, use the escape in the content property

\B1
3

Unicode U+00B1 belongs to the Latin-1 Supplement block (U+0080–U+00FF)

4

Prefer &plusmn; for readability—it’s the standard named entity for ±

5

Previous: Plus (+)   Next: Plus Sign Below (̟)

❓ Frequently Asked Questions

Use &#xB1; (hex), &#177; (decimal), &plusmn; (named), or \B1 in CSS content. All produce ±.
U+00B1 (PLUS-MINUS SIGN). Latin-1 Supplement block. Hex B1, decimal 177.
In tolerances, measurement uncertainty, scientific formulas, engineering specs, quadratic solutions, and any content showing a value that may be positive or negative.
HTML entities (&#177; or &plusmn;) go directly in markup. The CSS escape \B1 is used in stylesheets, typically in the content property of ::before or ::after. Same visual result, different layers of the stack.
Yes. &plusmn;, &#177;, and &#xB1; are equivalent in modern browsers and all render ±.

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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.

AWS Certified Developer – Associate (Credly)

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Plus (+) Plus Sign Below (̟)