HTML Entity for Fourth Root (∜)
What You'll Learn
How to display the Fourth Root symbol (∜) in HTML and CSS. This character is U+221C (FOURTH ROOT) in the Mathematical Operators block (U+2200–U+22FF). It denotes the fourth root operation in mathematics—for example, ∜16 = 2 or ∜x in an expression.
There is no named HTML entity for U+221C. Use ∜, ∜, or \221C in CSS content. Do not confuse ∜ with Square Root U+221A (√), Cube Root U+221B (∛), or Proportional To U+221D (∝). See cube root and the math entities hub for related radicals.
⚡ Quick Reference — Fourth Root
U+221CMathematical Operators (U+2200–U+22FF)
∜Hexadecimal reference
∜Decimal reference
—None (use numeric refs)
Name Value
──────────── ──────────
Unicode U+221C
Hex code ∜
HTML code ∜
Named entity —
CSS code \221CComplete HTML Example
This example shows U+221C using hexadecimal and decimal character references, plus a CSS content escape. There is no named HTML entity:
<!DOCTYPE html>
<html>
<head>
<style>
#point:after{
content: "\221C";
}
</style>
</head>
<body>
<p>Fourth Root using Hexadecimal: ∜</p>
<p>Fourth Root using HTML Code: ∜</p>
<p id="point">Fourth Root using CSS Entity: </p>
</body>
</html>🌐 Browser Support
U+221C is supported in modern browsers; use a math-capable font for best glyph quality:
👀 Live Preview
See Fourth Root (∜) in mathematical contexts:
🧠 How It Works
Hexadecimal Code
∜ references code point U+221C using hex digits 221C.
Decimal HTML Code
∜ is the decimal equivalent (8732) for the same character.
CSS Entity
\221C is the CSS escape for U+221C, used in the content property of ::before or ::after.
Same visual result
All three methods produce the fourth-root glyph: ∜. Unicode U+221C is in Mathematical Operators (U+2200–U+22FF). No named HTML entity exists.
Use Cases
Fourth Root (∜) commonly appears in:
Fourth root in expressions, equations, and problem-solving (e.g. ∜x, ∜16 = 2).
Real analysis and higher math involving roots and powers.
Textbooks, online courses, tutorials, and worksheets for school and college math.
Equation editors, calculators, and formula display components on the web.
Papers, reports, and technical docs with radical notation.
Unicode tables and Mathematical Operators glossaries.
Provide context (e.g. “fourth root of 16”) so screen readers convey the operation.
💡 Best Practices
Do
- Use
∜or∜for the standard fourth-root glyph - Use math fonts (Cambria Math, STIX Two Math) for clear operators
- Keep hex or decimal style consistent across the document
- Use
\221Conly inside CSScontent - Pair ∜ with operands (e.g. ∜16) for clear mathematical meaning
Don’t
- Confuse U+221C (∜) with U+221A (√ square), U+221B (∛ cube), or U+221D (∝ proportional)
- Use ∜ when you mean square root √ or cube root ∛
- Assume a named entity exists—U+221C has none
- Put CSS escape
\221Cin HTML text nodes - Mix hex and decimal styles randomly in one file
Key Takeaways
No named entity—use numeric references
∜ ∜For CSS stylesheets, use the escape in the content property
\221CU+221C FOURTH ROOT
Distinct from √ (square) and ∛ (cube)—each radical has its own code point
Three methods, one glyph — widely supported in modern browsers
❓ Frequently Asked Questions
∜ (hex), ∜ (decimal), or \221C in CSS content. There is no named HTML entity for U+221C.U+221C (Fourth Root). Mathematical Operators (U+2200–U+22FF). Hex 221C, decimal 8732.∜ or ∜) go in markup. The CSS escape \221C is used in stylesheets, typically in the content property of pseudo-elements. Both render ∜.∜ or ∜. See math entities for square root and related operators.Explore More HTML Entities!
Discover 1500+ HTML character references — math operators, symbols, arrows, and more.
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