List of letters used in mathematics and science

This list is about the meanings of the letters used in mathematics, science and engineering. SI units are indicated in parentheses. For the Unicode block
see Mathematical Alphanumeric Symbols.

This list is incomplete; you can help by expanding it.

Some common conventions:

Intensive quantities in physics are usually denoted with minuscules
while extensive are denoted with capital letters.
Most symbols are written in italics.
Vectors can be denoted in boldface.
Sets of numbers are typically bold or "blackboard bold".

Latin

Uppercase		Lowercase
A	Ampere area a blood type a spectral type vector potential Work set of algebraic numbers	a	SI prefix atto– acceleration reflectance
B	B meson a blood type boron luminance magnetic field a spectral type	b	Bottom quark
C	carbon degrees Celsius set of complex numbers coulomb molar heat capacity the C programming language specific heat capacity Cunningham correction factor	c	SI prefix Charm quark speed of light speed of sound
D	deuterium differential operator electric displacement D meson density	d	SI prefix deci– distance Down quark infinitesimal increment differential operator density
E	electric field energy SI prefix exa– expected value	e	Napier's constant electron positron electric charge
F	degrees Fahrenheit farad fluorine force Helmholtz free energy a spectral type	f	SI prefix femto– frequency
G	Einstein tensor SI prefix giga– Gibbs free energy gravitational constant Green's function Momentum a Spectral type	g	gram gravitational acceleration gravitational field distance metric of spacetime
H	auxiliary magnetic field enthalpy Hamiltonian Hankel function Heaviside step function Henry Higgs boson homology group Hubble constant hydrogen set of quaternions hat matrix	h	height hour Planck's constant spherical Hankel function
I	iodine impulse luminous intensity moment of inertia current	i	imaginary complex unit imaginary quaternion unit unit vector current row index
J	angular momentum Bessel function of the first kind current joule	j	electric current and current density radiant intensity spherical Bessel function of the first kind unit vector column index imaginary complex unit imaginary quaternion unit
K	kaon kelvin potassium sectional curvature a spectral type	k	Boltzmann constant imaginary quaternion unit SI prefix kilo– wave vector unit vector
L	angular momentum inductance (Henries) Lagrangian litre a spectral type	l	length litre mean free path
M	magnetization mass SI prefix mega– a spectral type torque	m	magnitude mass SI prefix milli– metre minute
N	Avogadro's number Bessel function of the second kind set of natural numbers newton nitrogen normal distribution normal vector	n	SI prefix nano– neutron refractive index spherical Bessel function of the second kind
O	big O notation a blood type oxygen a spectral type	o	small o notation
P	Legendre polynomial luminous flux phosphorus polarization power pressure probability projection	p	electric dipole moment momentum SI prefix pico- proton point of a space sound pressure
Q	electric charge quantity of heat set of rational numbers flow rate	q	electric charge generalized coordinate
R	curvature tensor electrical resistance radius set of real numbers	r	position (vector) radial polar coordinate radius
S	area entropy siemens sphere spin operator sulfur symmetric group	s	second Strange quark
T	a spectral type temperature tesla tritium	t	period time Top quark
U	potential energy uranium unitary operator	u	Up quark
V	potential energy vanadium volt voltage volume	v	velocity (m/s)
W	energy Lambert's W function tungsten watt W boson Work work function Wiener process	w	velocity (m/s)
X	random variable abscissa	x	abscissa real-valued argument variable to be determined vector,
Y	Bessel function of the second kind SI prefix yotta– yttrium ordinate luminance	y	ordinate SI prefix yocto- pixel row index
Z	atomic number impedance set of integers partition function (statistical mechanics) partition function (quantum field theory) Z boson SI prefix zetta– altitude	z	complex variable altitude SI prefix zepto-

Greek

Main article: Greek letters used in mathematics, science, and engineering

Uppercase		Lowercase
		α	Alpha particle Fine structure constant Angular acceleration
Β	Beta function	β	Beta particle Inverse temperature
Γ	Angular momentum Gamma function Christoffel symbols	γ	Euler–Mascheroni constant Gamma-ray (Photon) Photon Relativistic gamma factor
Δ	A macroscopic change in the value of a variable Laplace operator Delta particle	δ	Dirac delta function Infinitesimal quantity Kronecker delta
		ε	Infinitesimal quantity Permittivity
		ζ	Damping Ratio Riemann zeta function
		η	Distance metric of flat spacetime Efficiency Dynamic viscosity η-meson
Θ	Heaviside step function	θ	Angle Angular polar coordinate Temperature Theta role
		ι
		κ	Gravitational constant
Λ	Iwasawa algebra Lorentz transformation Lambda Hyperon	λ	Lagrangian multiplicator Lambda expression Thermal conductivity Wavelength
		μ	Absorption coefficient Chemical potential Magnetic dipole moment Mean SI prefix micro– Micron Muon Permeability Reduced mass
		ν	Frequency Kinematic viscosity Neutrino
Ξ	Cascade Hyperon	ξ	Riemann Xi function
		ο
Π	Product	π	Fundamental group Conjugate momentum Homotopy groups Number π Pion Prime-counting function Projection
		ρ	Density Electrical resistivity Radial polar coordinate ρ-meson
Σ	Sum Surface Sigma Hyperon	σ	Cross section Electrical conductivity Spin Standard deviation Stefan-Boltzmann constant
		τ	Tau lepton Torque Shear stress Time constant the number τ
		υ
Φ	Alternative symbol for Quantum mechanical wavefunction	φ	Angular polar coordinate Electric potential Euler's totient function Golden mean Phase Potential energy
		χ	Electric susceptibility
Ψ	Quantum mechanical wavefunction	ψ	Quantum mechanical wavefunction J/ψ particle
Ω	Chaitin's constant Ohm Solid angle Omega Hyperon	ω	Frequency (rad/s) angular velocity (rad/sec)

Å	angstrom
Ш	Tate–Shafarevich group (Ш(G ))
ш	shuffle product
ℵ	Cardinality of infinite sets
ℶ	Cardinality of infinite sets
∂	Partial derivative
∇	Del operator Gradient Divergence Curl

List of letters used in mathematics and science

Latin

Greek

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See also