Ω
Ω Omega Symbol
Omega (Ω) is the last letter of the Greek alphabet, used for the ohm in electronics; the separate ohm sign Ω (U+2126) is deprecated — use the Greek letter.
Also known as: omega symbol, ohms symbol, ohm sign, greek capital letter omega, ω.
Codes
| Symbol | Ω | |
| Lowercase | ω · U+03C9 | |
| Unicode | U+03A9 | |
| HTML entity (named) | Ω | |
| HTML entity (decimal) | Ω | |
| HTML entity (hex) | Ω | |
| CSS | \03A9 | |
| LaTeX | \Omega | |
| Windows Alt code | Alt + 234 |
How to type Ω (Omega Symbol)
WindowsAlt + 234
Hold Alt and type 234 on the numeric keypad, then release Alt (or type 03A9 then Alt + X in Word).
Mac⌥ + Z
Press Option + z.
Microsoft Word03A9, Alt + X
Type 03A9, then press Alt + X to convert it to Ω.
Google Docs
Insert → Special characters, then search “omega” or “greek capital letter omega”.
LaTeX\Omega
Use \Omega in math mode (\omega for lowercase ω). For the ohm unit, siunitx gives \ohm.
Usage
- In electronics Ω is the ohm, the SI unit of electrical resistance: a 470 Ω resistor.
- Which one to use: type the Greek letter Ω (U+03A9), not the ohm sign Ω (U+2126). Unicode deprecates U+2126 and normalization (NFC) silently converts it to U+03A9 anyway — so they are canonically the same character, and U+03A9 is the one that works everywhere.
- Lowercase ω (U+03C9) is a different character, used for angular frequency in physics and for ordinals in set theory.