Short answer: Tap an omega below to copy it. To type it: on Windows, Alt + 937 = Ω, Alt + 969 = ω (numeric keypad); on Mac, Option + Z = Ω, or use the Character Viewer for ω; in Word, type 03A9 then Alt + X; in HTML use Ω / ω; in LaTeX use \Omega / \omega.
Omega is the last of the 24 Greek letters — see the whole set in the Greek alphabet guide, or get any letter’s codes from the Alt Code Finder.
Omega (Ω uppercase, ω lowercase) is the 24th and final letter of the Greek alphabet — the “Ω” in “the Alpha and the Omega.” In science it’s everywhere: uppercase Ω is the ohm, the unit of electrical resistance, and lowercase ω is angular frequency. There’s also a subtle code-point wrinkle worth knowing.
Ω the letter vs Ω the ohm sign
There are two near-identical characters:
- Ω — Greek capital omega (U+03A9). The letter, and the one you should use for almost everything, including the ohm.
- Ω — the ohm sign (U+2126). A separate code point that looks identical and was added only for backward compatibility with older character sets.
Unicode’s own database treats the ohm sign as normalising to plain omega, and recommends using the Greek capital omega (U+03A9) for the ohm too. Most keyboards and tools produce U+03A9 anyway, and mixing the two has caused real document-conversion bugs. Bottom line: just use Ω (U+03A9) — the buttons and codes on this page all give it.
Quick reference
| Symbol | Name | Windows | Mac | HTML | LaTeX | Unicode |
|---|---|---|---|---|---|---|
| Ω | Greek capital omega | Alt + 937 | Option + Z | Ω | \Omega | U+03A9 |
| ω | Greek small omega | Alt + 969 | Viewer / Greek input | ω | \omega | U+03C9 |
| Ω | Ohm sign (legacy) | Alt + 8486 | Viewer | Ω | — | U+2126 |
| ℧ | Mho (conductance) | Alt + 8487 | Viewer | ℧ | \mho | U+2127 |
Type omega on Windows
- Alt codes: hold Alt, type on the numeric keypad (Num Lock on): Alt + 937 → Ω, Alt + 969 → ω. Use a Unicode-aware app (Word, browsers, email).
- Word: type
03A9and press Alt + X for Ω, or03C9+ Alt + X for ω. In an equation (Alt + =), type\Omegaor\omegathen Space. - Lots of Greek: add the Greek keyboard and switch with Windows + Space.
Type omega on Mac
- Ω: press Option + Z — the quickest omega on a Mac.
- ω: open the Character Viewer with Control + Command + Space, search “omega,” and double-click the lowercase form; or add the Greek input source.
Omega in Word
The 03A9 + Alt + X method above is quickest; otherwise Insert → Symbol → (Greek and Coptic). For the ohm in a formula, use an equation and \Omega — and remember it’s the same Ω you’d use in text.
Omega in HTML & LaTeX
- HTML:
Ω→ Ω,ω→ ω; numeric fallbacksΩ/ω(or hexΩ/ω) render the same. - LaTeX (math mode):
\Omegafor Ω,\omegafor ω. The mho/conductance sign is\mho.
Type omega on Linux & phone
- Linux: Ctrl + Shift + U, then
03a9(Ω) or03c9(ω), then Enter. - Phone: add a Greek keyboard (iPhone: Settings → General → Keyboard; Android: Gboard languages) and switch with the globe key, or copy Ω/ω from the tool above.
What omega means
- The ohm (Ω) — the SI unit of electrical resistance (and impedance in AC circuits), named after physicist Georg Ohm. It’s the Ω in Ohm’s law, V = I × R — a “100 Ω resistor,” for example.
- Angular frequency / velocity (ω) — lowercase omega, ω = 2πf, in AC and rotational physics (radians per second).
- Conductance (℧) — the “mho” (ohm spelled backwards), the reciprocal of resistance, an older name for the siemens.
- Solid angle (Ω) — measured in steradians in physics.
- Cosmology (Ω) — the density parameter of the universe.
- Computer science (Ω) — Big-Omega notation for an asymptotic lower bound, Ω(n).
- “The end” — as the last Greek letter, Ω signifies completion, as in “the Alpha and the Omega,” and appears in fraternity and sorority names.
Troubleshooting
| Problem | Fix |
|---|---|
| Alt + 937 gives the wrong character | Use the numeric keypad with Num Lock on, in a Unicode-aware app. |
| Ω shows as a box ▯ | Font lacks the glyph — switch to Segoe UI, Arial or Cambria Math. See symbol showing as a box. |
| My ohm sign breaks in file conversion | You’ve used U+2126; replace it with the Greek capital omega U+03A9, which Unicode recommends for the ohm. |
| ω looks like a “w” | It’s the Greek lowercase omega (U+03C9) — distinct from the Latin w. |
| Option + Z did nothing | It’s the US layout shortcut; on other layouts use the Character Viewer or Greek input source. |
Recap
- Windows → Alt + 937 (Ω) / Alt + 969 (ω); Word: 03A9 + Alt + X.
- Mac → Option + Z (Ω); Character Viewer for ω.
- Web →
Ω/ω. LaTeX →\Omega/\omega. - For the ohm → use Ω (U+03A9), not the legacy ohm sign.
Frequently asked questions
What does the omega symbol mean?
Omega is the 24th and final letter of the Greek alphabet, written Ω (uppercase) and ω (lowercase). Uppercase Ω is best known as the ohm, the unit of electrical resistance, and also denotes solid angle and other quantities; lowercase ω is angular frequency in physics. As the last letter, Ω also symbolises “the end,” as in “the Alpha and the Omega.”
Is the ohm sign the same as omega?
They look identical but are two Unicode characters: the ohm sign (Ω, U+2126) and the Greek capital omega (Ω, U+03A9). The ohm sign exists only for backward compatibility, and Unicode recommends using the Greek capital omega for the ohm as well. In practice, just type Ω (U+03A9).
How do I type omega on Windows?
Hold Alt and type 937 on the numeric keypad for Ω, or 969 for ω, in a Unicode-aware app. In Word, you can also type 03A9 (or 03C9) and press Alt + X. For lots of Greek, add the Greek keyboard layout and switch with Windows + Space.
How do I type omega on a Mac?
Press Option + Z for the capital Ω. For lowercase ω, open the Character Viewer with Control + Command + Space and search “omega,” or add the Greek input source. Option + Z is the US-layout shortcut, so on other layouts use the Character Viewer.
How do I type the ohm symbol for resistance?
Use the Greek capital omega Ω — Alt + 937 on Windows, Option + Z on Mac, or Ω in HTML. Unicode recommends this over the separate legacy “ohm sign” (U+2126), which looks the same but can cause problems in file conversion.
What does lowercase omega (ω) mean?
Lowercase ω is mainly angular frequency (or angular velocity) in physics, defined as ω = 2πf and measured in radians per second — common in alternating-current and rotational-motion equations. It also appears for other quantities depending on the field.
Written by Igor R.. Tested on Windows 11, macOS, Word and LaTeX. Symbol code points follow the Unicode Standard. Last updated July 2026.