How to type Lambda
To type Lambda (λ), press Alt + 955 on Windows, holding Alt while typing the digits on the numeric keypad, or write λ in HTML. On any system you can copy it from this page, or enter its codepoint U+03BB directly: Ctrl+Shift+U then 03bb on Linux, or 03bb then Alt+X in Microsoft Word.
Greek Small Letter Lamda
- Copy it
- Unicode
- U+03BB
- Windows
- Alt + 955 needs regedit
| Where | Shortcut | How |
|---|---|---|
| Windows | Alt + 955 | Above 255, so Windows will not accept it as typed. Copy the character instead. |
| Mac | N/A | Press the keys together. |
| HTML | λ | Paste this into HTML source. |
| Unicode | U+03BB | GREEK SMALL LETTER LAMDA |
Other greek symbols
Lambda is not the only name it goes by: people look for λ as wavelength too, and the search box on this site matches that as readily as the Unicode name.
λ lives in the Greek and Coptic block (U+0370-U+03FF), the Greek alphabet, used throughout mathematics and the sciences. Within Unicode it is classified as Ll, a lowercase letter. It has an uppercase counterpart and changes under case conversion. Its bidirectional class makes it left-to-right.
Its uppercase counterpart is Λ (U+039B). They are separate codepoints, so a byte comparison treats them as different characters even though a case-insensitive search does not.
How to type λ in Microsoft Word
In Microsoft Word, type 03bb and press Alt + X. Word reads the four characters before the cursor as a hex codepoint and replaces them, and pressing Alt + X again turns λ back into 03bb, which is the quickest way to check what a character really is.
What Lambda is used for
In mathematical notation λ is a variable: it stands for a quantity rather than acting on one, so an equation treats it the way it treats x, and the spacing around it is the spacing around a letter. That is the classification unicode-math gives it, and it is what decides how the symbol is set: $\muplambda$ in LaTeX, in maths mode rather than in a sentence.
The command is \muplambda rather than the \lambda most people reach for, and the difference is not cosmetic: mup is unicode-math for maths, upright, and this codepoint is the upright letter. Plain LaTeX's short command gives the sloped math-italic letter, which is a different character with a different codepoint. Copying λ into an equation gets you the upright one.
λ is a letter before it is a symbol, and on the Greek keyboard layout it is simply L: the key your keycap already calls L. That is the route when you are typing Greek rather than reaching for one character. How to type Greek on a keyboard has the whole map.
What Unicode says about Lambda
The code chart points from λ to latin small letter lambda (U+A7DB). These are the characters the standard thinks you might have meant instead, which makes them the ones worth checking when Lambda looks nearly right but not quite.
How Lambda behaves in software
λ is East Asian Ambiguous: one column in a Western locale and two in a CJK one. That is why a table that lines up on your machine can break on somebody else's, with no change to the text at all. It is a left-to-right character, so it holds that direction even inside a right-to-left paragraph.
What people ask about Lambda
What is the wavelength symbol called?
Unicode calls λ GREEK SMALL LETTER LAMDA, at U+03BB. It is also searched for as wavelength.
How to write lambda symbol?
You can press Alt + 955 on Windows, with Num Lock on and the digits typed on the numeric keypad. That produces λ.
Why is lambda used for wavelength?
λ is GREEK SMALL LETTER LAMDA, encoded at U+03BB. It is distinct from latin small letter lambda (U+A7DB), which the chart lists beside it precisely because they are confused for one another.
Where to find lambda symbol in word?
In Word, type 03bb and press Alt+X, which converts the codepoint you just typed into λ. Insert › Symbol › More Symbols finds it by its Unicode name, GREEK SMALL LETTER LAMDA. Google Docs has no Alt+X, so use Alt + 955 there, or Insert › Special characters and search the same name.
Every way to write Lambda
| Form | Value |
|---|---|
| Codepoint | U+03BB |
| Decimal | 955 |
| UTF-8 bytes | CE BB |
| UTF-16 bytes | 03 BB |
| HTML entity | λ |
| HTML numeric | λ or λ |
| CSS | \03BB |
| JavaScript | \u03BB |
| Python | \u03BB |
| URL-encoded | %CE%BB |
| LaTeX, in maths mode | $\muplambda$ |
| SVG | 03BB.svg · (SIL Open Font License) |
If λ arrives as λ
That is this exact character, undamaged: its two UTF-8 bytes CE BB are being read one at a time as Windows-1252. The Latin-1 range is where this happens most, because it is the range every legacy system thought it already handled. Nothing is lost, and retyping will not help: the fix is at the reading end, which has to be told the text is UTF-8. An empty rectangle is the opposite complaint, and means the encoding is right and the font has no glyph for U+03BB.