Greek symbols
Omega Symbol
Tap Ω or ω to copy. Code options below. Copy Ω or ω. Choose HTML or LaTeX when you need code instead.
Copies plain text. HTML and LaTeX copy code.
Ohm, Mho & accented omega
Need ohms? Use Ω (U+03A9) above. These choices keep their exact code points.
For exact legacy text. Prefer Ω for new text.
An older conductance symbol, not lowercase omega.
Accented Greek letter, not plain Ω.
Accented Greek letter, not plain ω.
Copying happens in your browser. Clipboard text is not sent to ToolNeko's server. Appearance and normalization can vary in the destination app.
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What does the omega symbol mean?
Omega is the last letter of the Greek alphabet: Ω is uppercase and ω is lowercase. The phrase alpha and omega uses the first and last letters to suggest a beginning and an end. There is no single meaning for every use of omega; a document's subject and notation matter.
In electrical measurements, Ω is the symbol for the ohm, the unit of resistance. Lowercase ω is often used for angular frequency or angular velocity in physics. Copy the case your equation calls for: a Latin w is not the Greek letter ω, and switching Ω to ω is not just a font change.
Omega Ω versus the legacy Ohm sign Ω
Ω is U+03A9 GREEK CAPITAL LETTER OMEGA. The almost identical Ω is U+2126 OHM SIGN. Unicode keeps the latter for compatibility and identifies Ω as the preferred representation. For new text, including resistance labels such as 10 Ω, choose the uppercase omega card.
These two code points are canonically equivalent: Unicode normalization can turn Ω into Ω. The legacy button here copies U+2126 exactly, without normalizing it, but another app may normalize pasted text. Its HTML button therefore uses Ω. The named HTML entity Ω actually resolves to Ω (U+03A9), not the legacy character.
The upside-down ℧ is U+2127 INVERTED OHM SIGN, also called mho. It is an older symbol for conductance, for which the modern SI unit is the siemens (S). It is neither lowercase omega nor an interchangeable replacement for Ω. Ώ and ώ are accented Greek letters with tonos, kept in a separate group below the main choices.
How to type omega on Windows, Mac, or a phone
In Microsoft Word on Windows, type 03A9 and press Alt + X for Ω, or type 03C9 and press Alt + X for ω. If the code follows another character, select just the code first. This is Word's Unicode conversion shortcut, not a universal shortcut for every Windows app or browser.
On Mac, open Edit → Emoji & Symbols to use Character Viewer, then search for omega. On iPhone or Android, tap a symbol above and paste into the destination field. If copying is blocked, the tool shows selectable text for manual copying. A destination app's font controls how the pasted character looks.
HTML entities and LaTeX commands
In HTML source, use Ω or Ω for uppercase Ω, and ω or ω for lowercase ω. Capitalization matters. The HTML buttons copy only the entity, with no styled span or other markup. For a normal chat or document, copy the large character instead.
In LaTeX math mode, use \Omega and \omega. The buttons copy the bare command so you can insert it into an existing equation; add math delimiters yourself when needed, for example $\omega$. A command pasted into an ordinary message stays text rather than automatically becoming a Greek letter.
Sources and standards
- Unicode — Greek and Coptic
- Unicode — Letterlike Symbols (Ohm and Mho)
- WHATWG — HTML named character references
- LaTeX Project — Math symbol definitions
- Microsoft — Unicode characters in Word
- Apple — Emoji and symbols on Mac
- NIST — SI units: ohm and siemens (Table 4)
- OpenStax — Rotational variables and angular velocity
Frequently asked questions
How do I copy the omega symbol?
Tap the large Ω or ω button and wait for the copied confirmation. This copies the character as plain text. The separate HTML and LaTeX buttons copy code instead.
Which omega symbol is used for ohms?
Use uppercase Ω, U+03A9. Unicode identifies it as the preferred representation over the legacy Ohm sign Ω, U+2126.
Is lowercase omega the same as w?
No. ω is Greek small letter omega, U+03C9. The Latin letter w is U+0077. Their shapes can look similar, but they are different characters.
Does Ω produce the legacy Ohm sign?
No. HTML Ω produces Ω (U+03A9). To encode the legacy Ω exactly, use Ω or Ω. A receiving app may still normalize it to Ω.
What is the upside-down omega symbol?
℧ is the inverted Ohm sign, also called mho, historically used for conductance. It is not lowercase omega. The modern SI unit of conductance is the siemens, symbol S.