Lowercase lambda λ is the eleventh Greek letter. Type 03BB then Alt+X in Word. It stands for wavelength in physics, the rate parameter of a Poisson distribution in statistics, and an anonymous function in programming, from Church's lambda calculus.
01 All shortcuts at a glance
| Platform | Shortcut | |
|---|---|---|
| Windows (any app) | Win+. or Win+; emoji/symbol picker, or Character Map (Win+R → charmap) |
|
| Mac | Control+Command+Space to open Character Viewer, search "Greek Small Letter Lambda" |
|
| Word / Outlook | Type 03BB, then press Alt+X |
|
| Linux (IBus) | Ctrl+Shift+U, then 03bb, then Enter |
|
| HTML / CSS | λ · \03bb (CSS) |
02 Step by step, per platform
A real, followable procedure for every platform, not a thin restatement of the shortcut.
Windows
- Open Character Map: Win+R, type charmap, press Enter.
- Search or scroll for Greek Small Letter Lambda (U+03BB).
- Select it, click Copy, then paste where you need it.
Mac
- Press Control+Command+Space to open the Character Viewer.
- Type "Greek Small Letter Lambda" in the search field.
- Double-click the result to insert it.
Microsoft Word
- Type 03BB.
- Press Alt+X immediately after, it converts the hex code to λ.
03 Characters in this set
04 Troubleshooting & confusables
| Looks like it | But it's actually | When to use |
|---|---|---|
| Λ (U+039B) | Greek capital lambda | A different quantity in most notations. Case is meaningful in physics. |
| ∧ (U+2227) | Logical and | A logic operator shaped like a capital lambda. Not a variable. |
| A upside down | A Latin letter rotated | Never. Rotated letters do not copy, search or read out correctly. |
05 FAQ
What is the Unicode code point for lambda?
Lowercase lambda is U+03BB and the capital is U+039B. There is no Windows Alt code for either.
What does λ mean in physics?
It is wavelength, the distance between successive peaks of a wave, usually in metres or nanometres. It also denotes the decay constant in radioactivity.
Why do lambdas in code have that name?
They come from lambda calculus, Alonzo Church's 1930s formal system for describing functions. Lisp adopted the term and nearly every modern language followed.
What does λ mean in statistics?
It is the rate parameter of a Poisson distribution, the average number of events in a fixed interval. It also names the regularisation strength in ridge and lasso regression.
How do I type it on a Mac?
Add the Greek input source in Keyboard settings, where lambda sits on the L key. The Character Viewer also finds it by name.