This is a complete reference to the Greek alphabet — all 24 letters with uppercase and lowercase forms, names, pronunciation, the nearest Latin equivalent, and the common uses you meet in maths, physics and engineering. It’s handy for reading formulas, learning the alphabet, or finding which letter a symbol like λ or Ω is.
All 24 Greek letters
| # | Upper | Lower | Name | Latin | Common scientific use |
|---|---|---|---|---|---|
| 1 | Α | α | Alpha | a | angle, significance level (statistics), fine-structure constant |
| 2 | Β | β | Beta | b | coefficient (statistics/ML), angle, beta radiation, beta function |
| 3 | Γ | γ | Gamma | g | Γ function, gamma radiation, Lorentz factor, photon |
| 4 | Δ | δ | Delta | d | Δ change in a quantity; δ small difference, Dirac delta |
| 5 | Ε | ε | Epsilon | e | small positive quantity, permittivity, eccentricity |
| 6 | Ζ | ζ | Zeta | z | Riemann zeta function, damping ratio |
| 7 | Η | η | Eta | ē | efficiency, viscosity |
| 8 | Θ | θ | Theta | th | angle, probability parameter, temperature (thermodynamics) |
| 9 | Ι | ι | Iota | i | rarely used in science; means “tiny amount” colloquially |
| 10 | Κ | κ | Kappa | k | curvature, dielectric constant, kappa statistic |
| 11 | Λ | λ | Lambda | l | wavelength, eigenvalue, decay constant, lambda calculus |
| 12 | Μ | μ | Mu | m | mean (statistics), micro- prefix (μm = micrometre), friction coefficient |
| 13 | Ν | ν | Nu | n | frequency (ν), kinematic viscosity |
| 14 | Ξ | ξ | Xi | x | random variable, xi particle in particle physics |
| 15 | Ο | ο | Omicron | o | rare in science (looks like the Latin o) |
| 16 | Π | π | Pi | p | circle constant ≈ 3.14159; Π product notation |
| 17 | Ρ | ρ | Rho | r | density, electrical resistivity, correlation coefficient |
| 18 | Σ | σ | Sigma | s | Σ summation; σ standard deviation, stress, Stefan-Boltzmann constant |
| 19 | Τ | τ | Tau | t | torque, time constant, shear stress, Kendall’s tau |
| 20 | Υ | υ | Upsilon | u | upsilon meson in particle physics |
| 21 | Φ | φ | Phi | ph | φ golden ratio ≈ 1.618, electric potential, wave function, latitude |
| 22 | Χ | χ | Chi | ch | chi-squared distribution (χ²), magnetic susceptibility |
| 23 | Ψ | ψ | Psi | ps | quantum wavefunction, polygamma function |
| 24 | Ω | ω | Omega | ō | Ω ohm (electrical resistance); ω angular frequency |
How the reference tool works
The page lists every letter in the order above, with a live search box that filters by glyph, name, Latin equivalent, or use. Searching “wavelength” jumps to lambda (λ). Searching “ohm” finds omega (Ω). Searching “density” returns rho (ρ).
A note on similar-looking letters
Several Greek letters look like Latin letters and are frequently confused:
- Α (Alpha) looks like Latin A — but it is always alpha in a Greek or mathematical context
- Ν (Nu) looks like Latin N
- Ρ (Rho) looks like Latin P — common source of confusion; ρ means density, not anything starting with P
- Τ (Tau) looks like Latin T
- Χ (Chi) looks like Latin X — but χ² is chi-squared, not x-squared
If you see an unusual letter in a formula and cannot identify it, the search in this tool will usually surface it by appearance or by looking up what the formula is about (e.g., “frequency” returns ν, “angle” returns α or θ).
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