τ
Unicode
U+03C4LaTeX
\tauHTML entity
HTML decimal
τMathML
<mi>τ</mi>Semantic identity and intent
Characters to distinguish
- π — Pi
- Δ — Delta
- μ — Population Mean
Use τ in the right format
Meaning and usage
Represents torque, time constant, shear stress, or the circle constant 2π.
Define tau and include units when it is a physical quantity.
Pronunciation: tau
Formula examples
\tau is used as a defined variable in an equation.How to type Tau
- Windows
- Open Character Map and search by name or Unicode U+03C4.
- macOS
- Open Character Viewer with Control–Command–Space and search by the symbol name.
- Microsoft Word
- In an equation, type \tau and press Space when Word supports the command.
- iPhone and iPad
- Copy and paste τ, or use a math/LaTeX app. The standard iOS keyboard may not expose every mathematical symbol.
- Android
- Copy and paste τ, or use a math keyboard or LaTeX editor. Keyboard layouts vary by device and app.
- Google Docs
- For plain text, paste τ or use Insert → Special characters. For structured math, use the equation editor and verify \tau.
- Excel
- Paste τ into a cell or use Insert → Symbol when available. Ordinary cells preserve the character but do not interpret LaTeX commands.
Common mistakes
- Do not substitute a visually similar Latin or differently styled character for τ; case and mathematical alphabet style can identify different quantities.
- For plain text, copy τ as U+03C4; for structured equations, use \tau in math mode. A look-alike glyph or image can break search, accessibility, or parsing when the intended character is Tau.
When to use τ
- Use τ in plain text when a Unicode character is appropriate and the destination preserves U+03C4.
- Use \tau in an equation editor when mathematical spacing or structure matters.
- Define the local meaning when Tau is used in greek with a field-specific convention.
Look-alikes and related characters
- π — Pi
- Δ — Delta
- μ — Population Mean
Font and compatibility notes
Glyph shape can vary by font. Verify the code point after copying, and prefer LaTeX or MathML for structured equations.
Continue the workflow
From Tau to a finished equation
- Copy the characterUse τ in plain text when Unicode is accepted.
- Choose a structured formatUse
\taufor LaTeX or the MathML snippet for accessible web equations. - Edit or convertOpen the value in the editor or converter without retyping it.
Review and source notes
Quality tier: specialist
Last reviewed: 2026-07-23
Review method: Catalog review of character identity and notation mappings.
Verified against: Unicode Standard, Unicode mathematical notation guidance, and established LaTeX/MathML syntax.
Reference sources
- The Unicode StandardUnicode Consortium — Character identity, encoding, names, and conformance.
- Unicode Character Code ChartsUnicode Consortium — Code points and official character charts.
Frequently asked questions
What does the Tau symbol mean?
Represents torque, time constant, shear stress, or the circle constant 2π.
What is the LaTeX command for τ?
Use \tau in a compatible math environment.
Can I copy τ as Unicode?
Yes. Use the copy button above to copy the Unicode character directly.