Lambda Symbol (λ) — How to Type, Copy & Paste the Greek Letter

Copy the Lambda Symbol

Here are both forms of the lambda symbol ready for you to copy and paste:

Λ — Capital Lambda (U+039B) — Copy this: Λ

λ — Lowercase Lambda (U+03BB) — Copy this: λ

Capital Lambda — Unicode: U+039B | HTML entity: Λ | CSS: \039B

Lowercase Lambda — Unicode: U+03BB | HTML entity: λ | CSS: \03BB

What Does the Lambda Symbol Mean?

Lambda (Λ / λ) is the 11th letter of the Greek alphabet. In the Greek numeral system, it has a value of 30. The letter originated from the Phoenician letter Lamed, which also gave rise to the Latin "L" and the Cyrillic "El" (Л).

The lowercase lambda (λ) is one of the most recognizable Greek letters in modern science and technology, appearing everywhere from physics equations to programming languages. Its distinctive triangular shape makes it easy to identify at a glance.

How to Type the Lambda Symbol on Windows

Here are the methods to type λ on a Windows PC:

• Alt Code (Capital): Hold Alt and type 9 2 3 on the numeric keypad. Release Alt to produce Λ.
• Alt Code (Lowercase): Hold Alt and type 9 5 5 on the numeric keypad for λ.
• Character Map: Press Win + R, type charmap, search for "Lambda," select it, and click Copy.
• Microsoft Word: Type 039B and press Alt + X for capital, or 03BB and Alt + X for lowercase.

How to Type Lambda on Mac

On macOS, you have several options:

• Character Viewer: Press Ctrl + Cmd + Space, search for "lambda," and double-click to insert.
• Greek Keyboard: Add the Greek keyboard in System Settings > Keyboard > Input Sources. Switch to it and press the "l" key for λ.
• Copy and Paste: Simply grab Λ or λ from this page.

How to Type Lambda on iPhone and Android

• iPhone: Add the Greek keyboard (Settings > General > Keyboard > Keyboards > Add New Keyboard > Greek). Switch keyboards and tap the lambda key.
• Android: Install a Greek keyboard from the Play Store. On Gboard, you may find it under Symbols or by long-pressing the "L" key on some layouts.
• Quickest Method: Copy λ from this page and paste it into any app.

Lambda in Physics

The lowercase lambda is a workhorse in physics notation:

• Wavelength (λ): The most common use — lambda represents the wavelength of a wave, measured in meters. The relationship λ = v/f (wavelength equals velocity divided by frequency) is fundamental to understanding light, sound, and all wave phenomena.
• Decay Constant: In nuclear physics, λ is the radioactive decay constant, which describes how quickly a radioactive substance breaks down.
• Thermal Conductivity: In thermodynamics, λ sometimes represents thermal conductivity — how well a material conducts heat.
• Linear Charge Density: In electromagnetism, λ denotes charge per unit length along a line.

Lambda in Mathematics

• Lambda Calculus: Developed by Alonzo Church in the 1930s, lambda calculus is a formal system for expressing computation based on function abstraction and application. It is the theoretical foundation of functional programming.
• Eigenvalues: In linear algebra, λ is the standard symbol for eigenvalues of a matrix.
• Lagrange Multipliers: In optimization problems, λ is used as the Lagrange multiplier.

Lambda in Programming

The lambda symbol has become deeply embedded in computer science:

• Lambda Functions: Most modern programming languages (Python, JavaScript, Java, C#, Ruby) support lambda expressions — anonymous functions that can be created inline. In Python, for example: lambda x: x * 2.
• AWS Lambda: Amazon Web Services named its serverless computing platform "Lambda" after the concept of lambda functions.
• Half-Life Developer: The video game company Valve uses a lambda (λ) as the logo for the Half-Life series — a clever reference to the physics concept of half-life decay.

Lambda in History and Culture

• Spartan Shields: The Spartans painted a lambda (Λ) on their shields, standing for Lacedaemon (the Greek name for Sparta). This is famously depicted in the movie "300."
• LGBTQ+ Symbol: The lambda was adopted as a gay rights symbol in the 1970s. It was chosen because of its association with liberation and its use in physics to represent energy.

Quick Reference Table

From wavelength calculations to serverless computing to Spartan shields, the lambda symbol is everywhere. Bookmark this page for quick access to copy Λ and λ whenever you need them.