Greek Alphabet — Letters, Names and Math Uses

The 24 letters of the Greek alphabet in order, each with its capital and small form, its Unicode code points and the quantities it usually denotes in math, statistics and science.

The 24 Greek letters

Code points are derived from the characters; the capitals run from U+0391 (Α) to U+03A9 (Ω), skipping U+03A2, which is unassigned. Sigma also has a word-final small form, ς (U+03C2).

Greek alphabet
#	Name	Capital	Small	Unicode (capital / small)	Common uses
1	Alpha	Α	α	U+0391 / U+03B1	Angles; significance level in statistics; alpha particles
2	Beta	Β	β	U+0392 / U+03B2	Angles; regression coefficients; type II error rate; beta particles
3	Gamma	Γ	γ	U+0393 / U+03B3	Γ(n) gamma function; γ photons; Euler–Mascheroni constant γ; Lorentz factor
4	Delta	Δ	δ	U+0394 / U+03B4	Δ change or difference; δ small change, Dirac delta, Kronecker delta
5	Epsilon	Ε	ε	U+0395 / U+03B5	ε a small positive quantity; permittivity; strain
6	Zeta	Ζ	ζ	U+0396 / U+03B6	ζ Riemann zeta function; damping ratio
7	Eta	Η	η	U+0397 / U+03B7	η efficiency; viscosity
8	Theta	Θ	θ	U+0398 / U+03B8	θ an angle; temperature in some texts
9	Iota	Ι	ι	U+0399 / U+03B9	Rarely used; ι inclusion map
10	Kappa	Κ	κ	U+039A / U+03BA	κ curvature; thermal conductivity; Cohen's kappa
11	Lambda	Λ	λ	U+039B / U+03BB	λ wavelength; eigenvalues; rate of a Poisson process; Λ cosmological constant
12	Mu	Μ	μ	U+039C / U+03BC	μ population mean; micro- prefix (10⁻⁶); coefficient of friction; permeability
13	Nu	Ν	ν	U+039D / U+03BD	ν frequency; degrees of freedom; kinematic viscosity
14	Xi	Ξ	ξ	U+039E / U+03BE	ξ random variable; Ξ grand canonical partition function
15	Omicron	Ο	ο	U+039F / U+03BF	Rarely used, because it looks like the Latin letter o
16	Pi	Π	π	U+03A0 / U+03C0	π ≈ 3.14159; Π product of a sequence
17	Rho	Ρ	ρ	U+03A1 / U+03C1	ρ density; resistivity; correlation coefficient
18	Sigma	Σ	σ	U+03A3 / U+03C3	σ standard deviation; Σ summation; σ electrical conductivity
19	Tau	Τ	τ	U+03A4 / U+03C4	τ torque; time constant; τ = 2π in some texts
20	Upsilon	Υ	υ	U+03A5 / U+03C5	Rarely used; Υ upsilon meson in physics
21	Phi	Φ	φ	U+03A6 / U+03C6	φ golden ratio; angles; Φ normal CDF; magnetic flux Φ
22	Chi	Χ	χ	U+03A7 / U+03C7	χ² chi-squared distribution and test
23	Psi	Ψ	ψ	U+03A8 / U+03C8	ψ wave function in quantum mechanics
24	Omega	Ω	ω	U+03A9 / U+03C9	ω angular frequency; Ω ohm (unit of resistance); Ω sample space

Sources: Unicode Consortium: Unicode chart: Greek and Coptic (U+0370–U+03FF)

Letters that look like Latin letters

Fourteen capitals (Α Β Ε Ζ Η Ι Κ Μ Ν Ο Ρ Τ Υ Χ) look the same as Latin capitals, so mathematics avoids them as symbols and uses the lower-case forms instead. Omicron (ο) is almost never used because it is indistinguishable from o.

Variant forms exist for several letters, such as ϑ (theta symbol, U+03D1), ϕ (phi symbol, U+03D5) and ϵ (lunate epsilon, U+03F5); fonts and textbooks differ on which is the default.

Greek Alphabet in Math and Science

The 24 Greek letters

Letters that look like Latin letters

References

Frequently asked questions