Omega Symbol (Ω ω): Meaning, Uses and Copy Paste

Uppercase / lowercase	Ω / ω
Position in alphabet	24 of 24
Unicode	U+03A9 / U+03C9
HTML entity	Ω / ω
HTML decimal	Ω / ω
LaTeX	\Omega / \omega
Word (type code, then Alt+X)	03A9 / 03C9
Windows Alt code	Alt + 234 (Ω)
Greek numeral value	800

The omega symbol (Ω ω) is the 24th and final letter of the Greek alphabet. Capital Ω is the unit symbol for the ohm, the measure of electrical resistance. Because omega comes last, it also stands for “the end,” as in the phrase “the alpha and the omega.”

What the Omega Symbol Means

Omega is the Greek letter for a long “o” sound. It follows psi (Ψ ψ) and closes the Greek alphabet in order. As a Greek numeral, omega was worth 800.

The name means “great o” or “big o.” In contrast, omicron means “small o.” Byzantine scholars gave both letters these descriptive names once the two vowels had come to sound alike.

Omega was a Greek invention, not a Phoenician borrowing. Ionian Greeks likely created it by opening up the circle of O, so they could mark a longer vowel. Later, the Ionic alphabet became the standard for all of Greece.

How to Pronounce Omega

Most Americans say “oh-MAY-guh,” and “oh-MEG-uh” is also common. In modern Greek, the name sounds like “oh-MEH-gah.” Today, Greek speakers pronounce ω exactly like ο, as a short “o.”

Uppercase vs Lowercase Omega

Capital omega (Ω) is a horseshoe shape with two small feet. Lowercase omega (ω) looks like a rounded w, with two curved bowls side by side. Unlike capital Ω, the lowercase form has no Latin twin, but it is easy to mistake for a w in some fonts.

When you write ω by hand, keep both bowls round at the bottom. Draw it in one smooth stroke, like two joined u shapes. A pointed w will confuse readers, especially in physics formulas where w can mean work or weight.

Omega Symbol in Science and Math

Both forms of the omega symbol have standard jobs in science. The capital usually marks units and large-scale quantities, while the lowercase marks rates of turning.

Electricity: The Ohm

Capital Ω is the symbol for the ohm, the SI unit of electrical resistance. According to NIST’s SI units page, 1 Ω equals 1 volt per ampere. So a 220 Ω resistor drops 2.2 volts when 10 milliamps flow through it.

The unit honors the German physicist Georg Simon Ohm. Today, Ω appears on every multimeter dial and resistor chart.

Physics: Angular Velocity and Frequency

Lowercase ω stands for angular velocity or angular frequency, measured in radians per second. For example, ω = 2πf links it with ordinary frequency f. Our physics symbols page covers related letters such as λ and ν.

Physicists also use capital Ω for solid angle. Meanwhile, cosmologists use Ω for the density parameter, which compares the universe’s actual density with a critical value.

Math and Computer Science

• Algorithms: Big Omega, Ω(n), gives a lower bound on how fast an algorithm’s running time grows.
• Set theory: ω is the first infinite ordinal, the order type of the natural numbers.
• Probability: Ω often names the sample space, the set of all possible outcomes.

Nutrition

In omega-3 and omega-6 fatty acids, “omega” refers to the last carbon in the fatty acid chain. The number tells you where the first double bond sits, counting from that omega end. So the name uses the letter’s meaning: the end.

For example, alpha-linolenic acid (ALA) in flaxseed and walnuts is an omega-3 fatty acid. Likewise, linoleic acid in many vegetable oils is an omega-6. Food labels often write these as ω-3 and ω-6.

How to Type the Omega Symbol

Capital omega has a Windows Alt code, and Macs have a handy shortcut for a lookalike. Here are the main methods.

• Windows Alt code: hold Alt and type 234 on the numeric keypad for Ω. Lowercase ω has no Alt code. See all Greek letters Alt codes.
• Microsoft Word: type 03A9 for Ω or 03C9 for ω, then press Alt+X.
• Mac shortcut: Option+Z types Ω, but it is the ohm sign (U+2126), not the Greek letter. It looks the same and works fine for ohms in most documents.
• Mac Greek letter: press Control + Command + Space and search “omega,” or add the Greek keyboard, where the V key types ω. Our Mac typing guide has the steps.
• LaTeX: \Omega and \omega.
• HTML: Ω or Ω for Ω, and ω or ω for ω.

If you paste text through a system that normalizes Unicode, the ohm sign usually turns into the Greek Ω. That is expected, because the two are defined as equivalent. The Unicode Greek chart lists the standard code points.

Omega in Culture and Everyday Use

The phrase “I am the Alpha and the Omega” appears in the Book of Revelation. It means “the first and the last,” using the first and final Greek letters. Our page on the alpha and omega symbol explains its history and use in Christian art.

Omega is also a familiar brand name. For instance, the Swiss watchmaker Omega took its name from a watch movement it launched in 1894. Its Speedmaster model later became famous as a watch worn on NASA’s Apollo missions. On campus, Omega Psi Phi was founded at Howard University in 1911, and it is one of several Greek-letter fraternities built around the letter.

In everyday speech, “omega” can mean the final stage of something. In contrast, “alpha” marks the first or leading one. You will see both words in tech releases, games and fiction.

Omega Quick Reference

Use this table to copy the right omega symbol code. Pick U+03A9 unless a system asks for the ohm sign.

Form	Character	Unicode	Alt code	HTML	LaTeX
Capital omega	Ω	U+03A9	Alt+234	Ω	\Omega
Lowercase omega	ω	U+03C9	—	ω	\omega
Ohm sign	Ω	U+2126	—	Ω	\ohm (siunitx)

In short, omega is the Greek long “o,” worth 800 as a numeral. It means ohms, angular velocity and, above all, the end. Next, compare it with the first letter, alpha, to see the full span of the alphabet.

Frequently Asked Questions

What does the omega symbol mean?

Omega (Ω ω) is the 24th and last letter of the Greek alphabet. In science, Ω is the symbol for the ohm, and ω usually means angular velocity or angular frequency.

Is the omega symbol the same as the ohm symbol?

They look the same, but Unicode has two characters: Greek omega (U+03A9) and the ohm sign (U+2126). Unicode recommends using the Greek omega, U+03A9, in both cases.

What is the Alt code for omega?

On Windows, hold Alt and type 234 on the numeric keypad to get Ω. Lowercase ω has no Alt code, so type 03C9 in Word and press Alt+X.

How do you type omega on a Mac?

Option+Z types Ω, but it is the ohm sign (U+2126). For the true Greek letter, use the Character Viewer (Control + Command + Space) or the Greek keyboard.

What does “the alpha and the omega” mean?

It means “the beginning and the end,” because alpha is the first Greek letter and omega the last. The phrase comes from the Book of Revelation.