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.

Latin and Greek letters are used in mathematics, science, engineering, and other areas where mathematical notation is used as symbols for constants, special functions, and also conventionally for variables representing certain quantities.

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 Buoyancy Bulk modulus Luminance Magnetic field A spectral type		b	Bottom quark Barn (10−24 cm2)
C	Carbon Degrees Celsius Set of complex numbers Coulomb Heat capacity The C programming language Cunningham correction factor Capacitance		c	SI prefix centi- Charm quark Speed of light Speed of sound Y-intercept Specific heat capacity
D	Deuterium Differential operator Electric displacement D meson Density Dimension		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 (Euler's number) Electron Positron Electric charge Unit Vector Eccentricity
F	Degrees Fahrenheit Farad Fluorine Force Helmholtz free energy A spectral type		f	SI prefix femto- Frequency Friction
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 Gluon
H	Auxiliary magnetic field Enthalpy Hamiltonian Hankel function Heaviside step function Henry Higgs boson Homology group Hubble constant Hydrogen Information entropy Set of quaternions Hat matrix		h	Height Hour Planck's constant Spherical Hankel function
I	Iodine 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 Impulse		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 Ratio of heat capacities (Cp/Cv)
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 Molar mass		m	Magnitude Mass SI prefix milli- Metre Minute Slope
N	Avogadro 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 Integer
O	Big O notation A blood type Oxygen A spectral type Origin		o	Small o notation
P	Active power Legendre polynomial Luminous flux Phosphorus Polarization Power Pressure Probability Projection Perimeter		p	Electric dipole moment Momentum SI prefix pico- Proton Point of a space Sound pressure
Q	Electric charge Quantity of heat Reactive power Set of rational numbers Flow rate		q	Electric charge Generalized coordinate Quark
R	Curvature tensor Electrical resistance Radius Set of real numbers Molar gas constant		r	Position (vector) Radial polar coordinate Radius
S	Apparent power Area Entropy Siemens Sphere Spin operator Sulfur Symmetric group		s	Second Strange quark Distance Specific heat capacity Specific entropy Isentropic
T	A spectral type Temperature Tesla Tritium Period		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	Width
X	Random variable Abscissa		x	Abscissa Real-valued argument Variable to be determined Vector Position
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 Compressibility factor		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 Difference		δ	Dirac delta function Infinitesimal quantity Kronecker delta
			ε	Infinitesimal quantity Permittivity
Ϝ	Digamma function
			ζ	Damping ratio Riemann zeta function
Η	H-theorem		η	Distance metric of flat spacetime Efficiency Dynamic viscosity η-meson
Θ	Heaviside step function		θ	Angle Angular polar coordinate Temperature Theta role
Κ	Kappa number		κ	Gravitational constant
Λ	Iwasawa algebra Lorentz transformation Lambda hyperon		λ	Lagrangian multiplicator Lambda expression Thermal conductivity Wavelength
			μ	Absorption coefficient Amplification factor Chemical potential Magnetic dipole moment Mean SI prefix micro- Micron Muon Permeability Reduced mass Coefficient of friction
			ν	Frequency Kinematic viscosity Neutrino
Ξ	Cascade hyperon		ξ	Riemann Xi function
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 sectionDivisor function Electrical conductivitySpectrum (matrix) Spin Standard deviation Stefan–Boltzmann constant
			τ	Tau lepton Torque Shear stress Time constant The number τ
ϒ	Upsilon meson
Φ	Alternative symbol for Quantum mechanical wavefunction Flux		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)

Other scripts

Hebrew

א	Cardinality of infinite sets
ב	Cardinality of infinite sets
ג	Gimel function
ת	Tav (number)

Cyrillic

Л	Lobachevsky function
Ш	Tate–Shafarevich group
ш	Shuffle product

Japanese

よ	Yoneda embedding
サ	Satake compactification

Modified Latin

Å	Angstrom
∀	Universal quantification
Đ	Dispersity
∂	Partial derivative
∃	Existential quantification
${\textstyle \hbar }$	Reduced Planck constant
Ø	Empty set
$\int$	Integral

Modified Greek

∇	Del operator Gradient Divergence Curl
ƛ	Reduced wavelength
∐	Coproduct

See also

• Blackboard bold letters used in mathematics
• Greek letters used in mathematics, science, and engineering
• Latin letters used in mathematics