How to use the Greek alphabet reference
- Leave Search empty to see all 24 letters, from alpha to omega.
- Type a name (sigma), a letter (σ or Σ) or a use (wavelength, ohm, density) to filter the list.
- Read the capital, small and variant forms, the pronunciation, typical uses and Unicode code points.
- Copy a letter from the Copy a letter list and paste it into your notes, document or spreadsheet.
What it does and when to use it
Greek letters appear on almost every page of maths, physics, chemistry and statistics: Δ for change, λ for wavelength, σ for standard deviation, Ω for ohms. When a textbook uses a symbol you cannot name, or you need to type one in a report, this page gives the name, how to say it and what it usually means.
Constants written with Greek letters, such as the Stefan–Boltzmann constant σ and the reduced Planck constant ħ, are listed with values in the physical constants table. The prefix micro (µ) is in the SI unit prefix table. To learn the letters by heart, put them into the flashcard maker, one “letter — name” per line.
How it works
The search looks for your text inside the letter’s name and its list of uses, ignoring case, and matches a pasted letter exactly in any of its forms. The “Typical uses” column lists common meanings, not every one. The same letter can mean different things in different subjects, so always check how your textbook defines it. Everything runs in your browser.
The 24 letters
| Letters | Name | Letters | Name | Letters | Name |
|---|---|---|---|---|---|
| Α α | alpha | Ι ι | iota | Ρ ρ | rho |
| Β β | beta | Κ κ | kappa | Σ σ | sigma |
| Γ γ | gamma | Λ λ | lambda | Τ τ | tau |
| Δ δ | delta | Μ μ | mu | Υ υ | upsilon |
| Ε ε | epsilon | Ν ν | nu | Φ φ | phi |
| Ζ ζ | zeta | Ξ ξ | xi | Χ χ | chi |
| Η η | eta | Ο ο | omicron | Ψ ψ | psi |
| Θ θ | theta | Π π | pi | Ω ω | omega |
Worked examples
Lambda. Searching “lambda” returns Λ and λ, said LAM-duh. λ stands for wavelength, a decay constant, eigenvalues and the rate of a Poisson process; Λ is the cosmological constant. The code points are U+039B and U+03BB.
From a use to a letter. Searching “ohm” finds omega: Ω is the ohm, solid angle and a density parameter in cosmology; ω is angular frequency and angular velocity.
Pasting a letter. Searching “σ” returns sigma with all three forms, Σ, σ and ς, and notes that σ stands for standard deviation, electrical conductivity and stress, among others.
Limits and tips
- Several capitals (Α, Β, Ε, Ζ, Η, Ι, Κ, Μ, Ν, Ο, Ρ, Τ, Χ) look like Latin letters but are different characters. Copy them from here rather than typing the Latin letter.
- Searching a use such as “resistance” finds nothing if that word is not in the uses list; try a related word such as “resistivity” or “ohm”.
Frequently asked questions
How do I type a Greek letter?
What are the variant forms?
Why does searching for µ find nothing?
Is the pronunciation the Greek one?
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