Omicron Symbol
About Omicron Symbol
ο is the Omicron Symbol, the lowercase form of the 15th letter of the Greek alphabet (Ο / ο). The Omicron Symbol ο is among the most common Greek letters in scientific and technical literature, frequently used for In mathematics it is the constant factor in big-O notation, and it became widely known through the COVID-19 variant.
【Pronunciation】 In English, ο is most often pronounced OM-ih-kron or oh-MY-kron (IPA: /ˈɒmɪkrɒn, oʊˈmaɪkrən/). This is simply the anglicized name of the Greek letter.
The lowercase Omicron Symbol ο is written as a distinct Greek glyph and is assigned codepoint U+03BF in the Greek and Coptic Unicode block. In plain or sans-serif fonts it can be mistaken for the Latin letter o, so verify the typeface or context.
【Historical Origin】 Omicron means 'small o'; its shape is almost identical to the Latin letter o and must be distinguished by context.
【Common Uses】 ο is highly active across disciplines: In mathematics it is the constant factor in big-O notation, and it became widely known through the COVID-19 variant. It often appears alongside the uppercase Sigma Σ and lowercase Sigma σ in formulas, papers, and engineering drawings.
How to Type Omicron Symbol
Windows Input
Method 1: Hold Alt and type 959 on the numeric keypad, then release Alt to get ο.
Mac Input
Method 2: Press Control + Command + Space to open the Character Viewer, search for 'greek' or 'Omicron Symbol', then select ο.
HTML/CSS Input
Method 3: HTML: ο or ο; CSS: content: "\03BF";
LaTeX Input
Method 4: Omicron has no dedicated LaTeX command; simply type the letter o in math mode to produce ο.
Omicron Symbol FAQ
How is ο pronounced?
The English pronunciation of ο is OM-ih-kron or oh-MY-kron (IPA: /ˈɒmɪkrɒn, oʊˈmaɪkrən/). It is the anglicized name of the Greek letter, used directly rather than described as 'lowercase ο'.
What is the difference between ο and the Latin letter o?
ο (U+03BF) is a Greek lowercase letter, whereas o is a Latin letter; their codepoints and glyphs differ. In a proper typeface ο and o are clearly distinct, but in plain text or sans-serif fonts they can be confused, so rely on context.
How do I type ο in Word, web pages, and LaTeX?
On Windows use Alt+959 on the numeric keypad; on Mac open the Character Viewer and search 'greek' or 'Omicron Symbol'; on the web use the numeric entity ο; in LaTeX simply type the letter o. For bulk use, copy ο directly from this page.