1. Latin characters

2. Greek characters

3. Other characters

4. See also

5. References

This is a list of common physical constants and variables, and their notations. Note that bold text indicates that the quantity is a vector.

Latin characters

Symbol	Meaning	SI unit of measure
	magnetic vector potential
	area	meter squared (m2)
	amplitude	meter
	atomic mass number
	acceleration	meters per second squared (m/s2)
	magnetic flux density also called the magnetic field density or magnetic induction	tesla (T), or equivalently, weber per square meter (Wb/m2)
	capacitance	farad (F)
	heat capacity	joule per kelvin (J⋅K−1)
	constant of integration	varied depending on context
	speed of light (in vacuum)	299,792,458 meter per second (m/s)
	speed of sound	340.29 meter per second (m/s)
	specific heat capacity	joule per kilogram per kelvin (J⋅kg−1⋅K−1)
	viscous damping coefficient	kilogram per second (kg/s)
	electric displacement field also called the electric flux density	coulomb per square meter (C/m2)
	density	kilograms per cubic meter (kg/m3)
	distance	meter (m)
	direction	unitless
	impact parameter	meter (m)
	diameter	meter (m)
	differential (e.g. )
	differential vector element of surface area A, with infinitesimally small magnitude and direction normal to surface S	square meter (m2)
	differential element of volume V enclosed by surface S	cubic meter (m3)
	electric field	newton per coulomb (N⋅C−1), or equivalently, volt per meter (V⋅m−1)
	energy	joule (J)
	Young's Modulus	pascal (Pa) or newton per square meter (N/m2)
	eccentricity	unitless
	2.71828... (base of the natural logarithm)	unitless
	elementary charge	coulomb (C)
	force	newton (N)
	Faraday constant	coulombs per mole (C⋅mol−1)
	frequency	hertz (Hz)
	function
	friction	newton (N)
	the gravitational constant	newton meter squared per kilogram squared (N⋅m2/kg2)
	acceleration due to gravity	meter per second squared (m/s2), or equivalently, newton per kilogram (N/kg)
	magnetic field strength	ampere per meter (A/m)
	Hamiltonian	joule (J)
	height	meter (m)
	Planck constant	joule second (J⋅s)
	reduced Planck constant	joule second (J⋅s)
	action	joule second (J⋅s)
	intensity	watt per square meter (W/m2)
	sound intensity	watt per square meter (W/m2)
	electric current	ampere (A)
	moment of inertia	kilogram meter squared (kg⋅m2)
	intensity	watt per square meter (W/m2)
	imaginary unit
	Cartesian x-axis basis unit vector	unitless
	free current density (not including bound currents due to polarization or magnetization)	ampere per square meter (A/m2)
	impulse	kilogram meter per second (kg⋅m/s)
	imaginary unit (electrical)
	jerk	meters per second cubed (m/s3)
	Cartesian y-axis basis unit vector	unitless
	kinetic energy	joule (J)
	Boltzmann constant	joule per kelvin (J/K)
	wavenumber, wave vector	radians per meter (m−1)
	Cartesian z-axis basis unit vector	unitless
	inductance	henry (H)
	luminosity	watt (W)
	angular momentum	newton meter second (N⋅m⋅s or kg⋅m2⋅s−1)
	Lagrangian	joule (J)
	length	meter (m)
	magnetization	ampere per meter (A/m)
	moment of force often simply called moment or torque	newton meter (N⋅m)
	mass	kilogram (kg)
	normal vector	unit varies depending on context
	atomic number	unitless
	refractive index	unitless
	principal quantum number	unitless
	amount of substance	mole
	power	watt (W)
	probability	unitless
	momentum	kilogram meter per second (kg⋅m/s)
	pressure	pascal (Pa)
	electric charge	coulomb (C)
	Heat	joule (J)
	electric charge	coulomb (C)
	electrical resistance	ohm (Ω)
	Ricci tensor
	radiancy
	gas constant	joule per mole per kelvin (J⋅mol−1⋅K−1)
	radius vector (position)	meter (m)
	radius or distance	meter (m)
	surface area	m2
	entropy	joule per kelvin (J/K)
	action	joule second (J⋅s)
	arc length	meter (m)
	displacement	meter (m)
	period	second (s)
	temperature	kelvin (K) or Celsius (C)
	time	second (s)
	four-velocity	meter per second (m/s)
	potential energy	joule (J)
	internal energy	joule (J)
	relativistic mass	kilogram (kg)
	energy density	joule per cubic meter (J/m3) or joule per kilogram (J/kg) depending on the context
	voltage also called electric potential difference	volt (V)
	volume	cubic meter (m3)
	shear force
	velocity	meter per second (m/s)
	mechanical work	joule (J)
	width	meter (m)
	a generic unknown	varied depending on context
	displacement	meter (m)
	electrical impedance	ohm (Ω)

Greek characters

Symbol	Name	Meaning	SI unit of measure
	alpha	angular acceleration	radian per second squared (rad/s2)
		fine-structure constant	unitless
	beta	velocity in terms of the speed of light c	unitless
	gamma	Lorentz factor	unitless
		photon
		gamma ray
		shear strain
		heat capacity ratio	unitless
	delta	change in a variable (e.g. )	unitless
		Laplace operator	per square meter (m−2)
		displacement (usually small)
	epsilon	permittivity	farad per meter (F/m)
		strain	unitless
	epsilon nought	vacuum permittivity constant
	zeta	damping ratio	unitless
	eta	energy efficiency	unitless
		coefficient of viscosity also called simply viscosity	pascal second (Pa⋅s)
		jerk	meter per second cubed (m/s3)
	theta	angular displacement	radian (rad)
	kappa	torsion coefficient also called torsion constant	newton meter per radian (N⋅m/rad)
	lambda	cosmological constant	per second squared (s−2)
		wavelength	meter (m)
		eigenvalue	non-zero vector
fuel to oxidizer ratio in rocket fuel
	mu	magnetic moment	ampere square meter (A⋅m2)
		coefficient of friction	unitless
		dynamic viscosity	pascal second (Pa⋅s)
		permeability (electromagnetism)	henry per meter (H/m)
		reduced mass	kilogram (kg)
		gravitational parameter
	mu nought	vacuum permeability constant
	nu	frequency	hertz (Hz)
		kinematic viscosity	meters squared per second (m2/s)
	pi	3.14159... (irrational number)	unitless
	rho	mass density usually simply called density	kilogram per cubic meter (kg/m3)
		free electric charge density, not including dipole charges bound in a material	coulomb per cubic meter (C/m3)
		resistivity	ohm meter (Ω⋅m)
	sigma	summation operator
	sigma	electrical conductivity	siemens per meter (S/m)
		normal stress
	tau	torque	newton meter (N⋅m)
		shear stress
		time constant	second (s)
		6.28318... (2π)	unitless
	phi	field strength	unit varies depending on context
		magnetic flux	weber (Wb)
	phi	electric potential	volt (V)
		Higgs field work function
	psi	wave function	m−3/2
	omega	angular frequency	radian per second (rad/s)
	omega	electric resistance	ohm

Other characters

Symbol	Name	Meaning	SI unit of measure
	nabla dot	the divergence operator often pronounced "del dot"	per meter (m−1)
	nabla cross	the curl operator often pronounced "del cross"	per meter (m−1)
	nabla	delta (differential operator)
	Delta	the Laplace operator		"der", "dow", "die", "partial" or simply "d"	partial derivative (e.g. )
	D'Alembert operator

See also

• List of letters used in mathematics and science
• List of mathematical symbols
• Roman letters used in mathematics
• Greek letters used in mathematics, science, and engineering
• Physical constant
• Physical quantity
• International System of Units
• ISO 31

References

• Cathorops taylori
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• Cath Ouellette
• Cat House (Riga)
• Cathrin Adams
• Cathrine Curtis
• Cathrine Dahl
• Cathrine Dufour
• Cathrine Gyldensted
• Cathrine MacKinnon
• Cathrine Marie Gielstrup
• Cathrine Morris
• Cathrine Tuivaiti
• Cathrine Wessel
• Cathrine wessel
• Cathrine Winnes
• Cathriona White
• Cathryn Adams
• Cathryn Bristow
• Cathryn McCarthy
• Cathryn M. Lewis
• Cathryn O'Loughlin MacCarthy
• Cathryn O'Loughlin McCarthy
• Cathryn Sophia