Greek Alphabet
for Math & Science

Complete reference for Greek letters with their names, symbols, and common uses in mathematics and science.

Alpha

Beta

Gamma

Delta

Epsilon

Zeta

Eta

Theta

Iota

Kappa

Lambda

Omicron

Rho

Sigma

Tau

Upsilon

Phi

Chi

Psi

Omega

Upper	Lower	Name	Sound	Common Uses
Α	α	Alpha	a	Angles, alpha particles, significance level in statistics
Β	β	Beta	b	Beta particles, beta coefficient in finance
Γ	γ	Gamma	g	Gamma rays, gamma function, surface tension
Δ	δ	Delta	d	Change/difference, Kronecker delta, small quantities
Ε	ε	Epsilon	e	Small positive quantities, permittivity, strain
Ζ	ζ	Zeta	z	Riemann zeta function, damping ratio
Η	η	Eta	ē	Efficiency, viscosity, eta mesons
Θ	θ	Theta	th	Angles, temperature, theta functions
Ι	ι	Iota	i	Index notation, imaginary unit (alternative)
Κ	κ	Kappa	k	Curvature, dielectric constant, condition number
Λ	λ	Lambda	l	Wavelength, eigenvalues, decay constant, lambda calculus
Μ	μ	Mu	m	Micro prefix (μ), mean, coefficient of friction
Ν	ν	Nu	n	Frequency, kinematic viscosity, degrees of freedom
Ξ	ξ	Xi	x	Random variables, damping ratio
Ο	ο	Omicron	o	Big O notation (uppercase)
Π	π	Pi	p	π ≈ 3.14159..., product notation (Π)
Ρ	ρ	Rho	r	Density, correlation coefficient, resistivity
Σ	σ	Sigma	s	Sum notation (Σ), standard deviation (σ), stress
Τ	τ	Tau	t	Torque, time constant, tau (2π), shear stress
Υ	υ	Upsilon	u	Upsilon mesons, specific volume
Φ	φ	Phi	ph	Golden ratio (φ ≈ 1.618), magnetic flux, angles
Χ	χ	Chi	ch	Chi-squared distribution, electric susceptibility
Ψ	ψ	Psi	ps	Wave function, angles, psychology symbol
Ω	ω	Omega	ō	Ohm (Ω), angular velocity (ω), last/end

Most Used Symbols

π ≈ 3.14159... is the ratio of a circle's circumference to its diameter. Used extensively in geometry, trigonometry, and physics.

Uppercase Σ represents summation. Lowercase σ represents standard deviation in statistics or stress in physics.

Represents change or difference. Δx means "change in x". Lowercase δ is used for small variations.

The most common symbol for unknown angles in trigonometry and geometry. Also used for angular position.

Represents wavelength in physics, eigenvalues in linear algebra, and decay constants in nuclear physics.

φ ≈ 1.618... is the golden ratio, found in art, architecture, and nature. Also used for magnetic flux and angles.