Alpha Symbol (Α α): Meaning, Uses and Copy Paste

Uppercase / lowercase	Α / α
Position in alphabet	1 of 24
Unicode	U+0391 / U+03B1
HTML entity	Α / α
HTML decimal	Α / α
LaTeX	A (no command) / \alpha
Word (type code, then Alt+X)	0391 / 03B1
Windows Alt code	Alt + 224 (α)
Greek numeral value	1

The alpha symbol (Α α) is the first letter of the Greek alphabet. It stands for the sound “a,” and it also means “the first” or “the best” in everyday English. Below, you will find what it means, where scientists use it, and how to type it on any device.

What the Alpha Symbol Means

Alpha is letter 1 of 24 in the Greek alphabet in order. It also had the value 1 in the Greek numeral system. To mark a number, scribes added a small stroke after the letter, so αʹ meant 1. A stroke before it, as in ͵α, meant 1,000. In US English, people say it “AL-fuh,” while modern Greek speakers say “AHL-fah.”

The name comes from the Semitic letter aleph, which meant “ox,” according to Britannica. In Phoenician, aleph marked a breathing sound, since that script wrote no vowels. The Greeks then turned it into the vowel “a.” You can trace that story in our guide to the Phoenician alphabet.

Alpha also gave English the word “alphabet.” That word joins alpha and beta, the first two letters. So the whole system is named after its opening pair.

Uppercase vs Lowercase Alpha

Capital alpha (Α) looks exactly like a Latin capital A. However, computers treat them as two different characters. Capital alpha is U+0391, while the Latin A is U+0041.

Lowercase alpha (α) is a rounded loop with a small tail on the right. In handwriting, it resembles a small fish or a slanted “a.” However, do not confuse it with the proportional sign ∝ (U+221D). That sign looks similar, but it is a math operator, not a letter. Another lookalike is ɑ (U+0251), the Latin alpha used in phonetic spelling. Linguists use it for the “a” sound in “father.”

Alpha in Math and Science

The lowercase alpha symbol is one of the most common Greek letters in technical writing. Its meaning depends on the field, so always check the context.

Math and Geometry

In geometry, α often names the first unknown angle in a figure. Then β and γ name the next angles. Mathematicians also use α as a general parameter or a root of an equation.

Physics

An alpha particle is a helium-4 nucleus, made of two protons and two neutrons. Ernest Rutherford named alpha rays in 1899, along with beta rays. In mechanics, α also stands for angular acceleration. For more examples, see our list of Greek letters in physics.

Statistics

In hypothesis testing, α is the significance level. In other words, it is the chance of rejecting a true null hypothesis, called a Type I error. A common value is α = 0.05. Our guide to statistics symbols covers this and related letters.

Chemistry and Biology

Biochemists use α for structures and positions. For example, the alpha helix is a common coiled shape in proteins. Also, the alpha carbon is the central carbon atom in an amino acid, next to the carboxyl group.

In chemistry, α also marks the first position next to a functional group. Similarly, α appears in names like alpha-tocopherol, a form of vitamin E. In each case, the letter is a label for “first” or “primary.”

Finance and Astronomy

In investing, alpha measures a fund’s return above its benchmark. Similarly, beta measures how much a stock moves with the market. In astronomy, Johann Bayer’s 1603 star atlas began labeling bright stars with Greek letters. As a result, we have names like Alpha Centauri.

How to Type the Alpha Symbol

The fastest option is to copy α or Α from the card at the top of this page. Otherwise, use one of these methods. Each one inserts the real Greek letter, not a lookalike.

• Windows Alt code: hold Alt and type 224 on the numeric keypad for α. Capital Α has no Alt code. See all Greek letter Alt codes.
• Microsoft Word: type 03B1 and press Alt+X for α, or 0391 for Α. Microsoft explains this in its Unicode shortcut guide. It works in Outlook too.
• Mac: press Fn+E (or Control+Command+Space) to open the Character Viewer, then search “alpha.” For a Greek keyboard, read how to type Greek letters on Mac.
• LaTeX: use \alpha for α. Capital alpha has no command, so just type a roman A.
• Windows symbol panel: press Win + . (period), open the symbols tab, and pick α from the Greek set. This works in most apps, including browsers.
• HTML: use α or α for α, and Α or Α for Α.

Alpha in Culture and Everyday Use

Because alpha comes first, English uses it for anything early or leading. For example, an “alpha version” of software is the earliest test release. Then a beta version follows for wider testing.

The phrase “Alpha and Omega” means the beginning and the end. It comes from the Book of Revelation, and our Alpha and Omega symbol guide explains its history. Omega, the last letter, closes the alphabet just as alpha opens it.

Alpha also leads many college letter names. For instance, Alpha Phi Alpha was founded at Cornell University in 1906. It was the first intercollegiate Greek-letter fraternity for Black students. Browse more names in our list of Greek letters for fraternities and sororities.

Alpha Symbol Quick Reference

Use this table to grab the right code for each form of alpha. Also, keep in mind that capital alpha needs Word or HTML, since it has no Alt code.

Item	Capital Α	Lowercase α
Unicode	U+0391	U+03B1
HTML entity	Α	α
HTML decimal	Α	α
Windows Alt code	None	Alt+224
Word (Alt+X)	0391	03B1
LaTeX	A	\alpha
Transliteration	A	a
Numeral value	1	1

Need codes for other letters too? Browse every code point and entity in our Greek Unicode and HTML code list. It uses the same format as this table.

Frequently Asked Questions

What does the alpha symbol mean?

Alpha (Α α) is the first letter of the Greek alphabet and stands for the sound “a.” Because it comes first, it also means “the first” or “the beginning.” In science, α labels things like angles, alpha particles and significance levels.

How do I type the alpha symbol on a keyboard?

On Windows, hold Alt and type 224 on the numeric keypad to get α. In Word, type 03B1 and press Alt+X. On a Mac, open the Character Viewer and search for “alpha,” or switch to a Greek keyboard.

Is the capital alpha symbol the same as the letter A?

It looks the same, but it is a different character. Capital alpha is U+0391, while the Latin A is U+0041. Search engines and spell checkers treat them as different letters, so use the right one.

What is alpha in statistics?

In statistics, α is the significance level of a hypothesis test. It is the probability of rejecting a true null hypothesis, also called a Type I error. A common choice is α = 0.05.

What does Alpha and Omega mean?

Alpha is the first Greek letter and omega is the last. So “Alpha and Omega” means the beginning and the end. The phrase appears in the Book of Revelation as a title for God.