Eta Symbol
About Eta Symbol
η is the Eta Symbol, the lowercase form of the 7th letter of the Greek alphabet (Η / η). The Eta Symbol η is among the most common Greek letters in scientific and technical literature, frequently used for In physics and engineering it represents efficiency, viscosity, and the learning rate in neural networks.
【Pronunciation】 In English, η is most often pronounced EE-tuh or AY-tuh (IPA: /ˈiːtə, ˈeɪtə/). This is simply the anglicized name of the Greek letter.
The lowercase Eta Symbol η is written as a distinct Greek glyph and is assigned codepoint U+03B7 in the Greek and Coptic Unicode block. In plain or sans-serif fonts it can be mistaken for the Latin letter n, so verify the typeface or context.
【Historical Origin】 Eta derives from the Phoenician letter heth and is common in thermodynamics and fluid mechanics.
【Common Uses】 η is highly active across disciplines: In physics and engineering it represents efficiency, viscosity, and the learning rate in neural networks. It often appears alongside the uppercase Sigma Σ and lowercase Sigma σ in formulas, papers, and engineering drawings.
How to Type Eta Symbol
Windows Input
Method 1: Hold Alt and type 951 on the numeric keypad, then release Alt to get η.
Mac Input
Method 2: Press Control + Command + Space to open the Character Viewer, search for 'greek' or 'Eta Symbol', then select η.
HTML/CSS Input
Method 3: HTML: η or η or η; CSS: content: "\03B7";
LaTeX Input
Method 4: Use the \eta command in LaTeX math mode to produce η.
Eta Symbol FAQ
How is η pronounced?
The English pronunciation of η is EE-tuh or AY-tuh (IPA: /ˈiːtə, ˈeɪtə/). It is the anglicized name of the Greek letter, used directly rather than described as 'lowercase η'.
What is the difference between η and the Latin letter n?
η (U+03B7) is a Greek lowercase letter, whereas n is a Latin letter; their codepoints and glyphs differ. In a proper typeface η and n are clearly distinct, but in plain text or sans-serif fonts they can be confused, so rely on context.
How do I type η in Word, web pages, and LaTeX?
On Windows use Alt+951 on the numeric keypad; on Mac open the Character Viewer and search 'greek' or 'Eta Symbol'; on the web use the HTML entity η; in LaTeX use \eta. For bulk use, copy η directly from this page.