Home › Greek Letters › Tau Symbol
Tau Symbol (τ)
Tau (τ) is a letter of the Greek alphabet — the T of Greek
Tau Symbol codes
| Code | Value |
|---|---|
| Unicode code point | U+03C4 |
| Unicode name | Greek Small Letter Tau |
| HTML named entity | τ |
| HTML decimal | τ |
| HTML hex | τ |
| CSS content code | \3C4 |
| JavaScript / JSON | \u03C4 |
| Windows Alt code | No standard Alt code — copy it from the card above |
Tau Symbol variants (5)
5 related glyphs — click any tile to copy it. Tiles with a page open that symbol's own page.
Meaning & usage
Tau is the T of Greek — championed by some mathematicians as the true circle constant (τ = 2π), and the name of a particle and a protein in brain science. The capital form is Τ and the lowercase is τ; the lowercase is usually the one worth copying, because several Greek capitals look exactly like Latin letters.
Greek letters are the spare alphabet of science: when Latin letters run out, formulas reach for these. This page gives you both forms, every code, and the typing routes.
Examples in use
- τ in a formula or report
- Τ as the capital form
- Copy τ into homework, slides or a username
How to type the tau symbol
Windows
There is no Alt code or direct key for τ. In Microsoft Word, type 03C4 and press Alt+X to convert it. Everywhere else, click the Copy button at the top of this page and paste it (Ctrl+V) — that always works.
Mac
There is no Option-key shortcut for τ on a Mac. Open the Character Viewer with Control+Command+Space, search for "Tau Symbol", and double-click to insert — or copy it from this page.
iPhone & Android
Most phone keyboards have no built-in key for τ. Open this page on your phone, tap Copy, then paste it into your message or bio. (On Android, Gboard's emoji search finds some symbols by name.)
Linux
Press Ctrl+Shift+U, type 03c4 and press Enter (works in most GTK apps and terminals with IBus). Or copy it from this page.
Frequently asked questions
How do I type τ on a keyboard?
There is no standard Alt code for τ. Copy it from this page, type it in Word with the hex code 03C4 followed by Alt+X, or add the Greek keyboard layout in your system settings.
What is the capital of Tau?
The capital is Τ (U+03A4) and the lowercase is τ (U+03C4). Both are in the variants grid on this page.
Why does τ sometimes show as a box or question mark?
The box (called tofu) means the device or font viewing it has no drawing for U+03C4 (Greek Small Letter Tau). The character itself is fine — try a different font or a newer device, or use one of the variants on this page.
Is the Tau Symbol free to use?
Yes. τ is a standard Unicode text character published in the Unicode Character Database. You may use it in personal and commercial documents, designs and products without permission or payment.
Related symbols
More in Greek Letters · All symbols
Data: Unicode Character Database · Page updated 2026-11-13