List of common physics notations

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
	vector potential">Vector (geometry)">vector potential	tesla meter
	area	square meter
	amplitude	meter
	atomic mass number	unitless
	acceleration	meter per second squared
	magnetic flux density also called the magnetic field density or magnetic induction	tesla, or equivalently, weber per square meter
	capacitance	farad
	heat capacity	joule per kelvin
	constant of integration	varied depending on context
	speed of light	299,792,458 meters per second
	speed of sound	meter per second
	specific heat capacity	joule per kilogram per kelvin
	viscous damping coefficient	kilogram per second
	electric displacement field also called the electric flux density	coulomb per square meter
	density	kilogram per cubic meter
	diameter	meter
	distance	meter
	direction	unitless
	impact parameter	meter
	differential	varied depending on context
	differential vector element of surface area A, with infinitesimally small magnitude and direction normal to surface S	square meter
	differential element of volume V enclosed by surface S	cubic meter
	electric field	newton per coulomb, or equivalently, volt per meter
	energy	joule
	Young's modulus	pascal or newton per square meter
	eccentricity	unitless
	Euler's number	unitless
	electron	unitless
	elementary charge	coulomb
	force	newton
	Faraday constant	coulombs per mole
	frequency	hertz
	function	unitless
	friction	newton
	electrical conductance	siemens
	universal gravitational constant	newton meter squared per kilogram squared
	shear modulus	pascal or newton per square meter
	gluon field strength tensor	inverse length squared
	acceleration due to gravity	meters per second squared, or equivalently, newtons per kilogram
	magnetic field strength	ampere per meter
	Hamiltonian	joule
	enthalpy	joule
	thermal current	watt
	height	meter
	Planck constant	joule second
	reduced Planck constant	joule second
	action	joule second
	intensity	watt per square meter
	sound intensity	watt per square meter
	electric current	ampere
	moment of inertia	kilogram meter squared
	intensity	watt per square meter
	imaginary unit	unitless
	electric current	ampere
	Cartesian x-axis basis unit vector	unitless
	current density	ampere per square meter
	impulse	kilogram meter per second
	jerk	meter per second cubed
	imaginary unit	unitless
	Cartesian y-axis basis unit vector	unitless
	kinetic energy	joule
	wave vector	radian per meter
	Boltzmann constant	joule per kelvin
	wavenumber	radian per meter
	stiffness	newton per meter
	Cartesian z-axis basis unit vector	unitless
	angular momentum	newton meter second
	inductance	henry
	luminosity	watt
	Lagrangian	joule
	Lagrangian density	joule per cubic meter
	length	meter
ℓ	azimuthal quantum number	unitless
	magnetization	ampere per meter
	moment of force often simply called moment or torque	newton meter
	mass	kilogram
	normal vector	unit varies depending on context
	atomic number	unitless
	refractive index	unitless
	principal quantum number	unitless
	amount of substance	mole
	power	watt
	active power	watt
	probability	unitless
	momentum	kilogram meter per second
	pressure	pascal
	electric charge	coulomb
	heat	joule
	Reactive Power	volt-ampere reactive
	electric charge	coulomb
	electrical resistance	ohm
	Ricci tensor	reciprocal square meter
	radiancy	meter per second
	gas constant	joule per mole per kelvin
	radius vector (position)	meter
	radius or distance	meter
	surface area	square meter
	entropy	joule per kelvin
	action	joule second
	apparent power	Volt-Ampere
	displacement	meter
	arc length	meter
	distance	meter
	period	second
	temperature	kelvin or Celsius
	kinetic energy	joule
	time	second
	four-velocity	meter per second
	potential energy	joule
	internal energy	joule
u	initial velocity	meter per second
	relativistic mass	kilogram
	energy density	joule per cubic meter
	specific energy	joule per kilogram
	voltage also called electric potential difference	volt
	volume	cubic meter
	shear force	newton
	velocity	meter per second
	weight	newton
	mechanical work	joule
	width	meter
	electrical reactance	ohm
	position vector	meter
	displacement	meter
	a generic unknown	varied depending on context
	admittance	siemens
	compressibility factor	unitless
	electrical impedance	ohm
	impedance of free space	ohm

Greek characters

Symbol	Name	Meaning	SI unit of measure
	alpha	alpha particle
	alpha	angular acceleration	radian per second squared
	alpha	fine-structure constant	unitless
	beta	velocity in terms of the speed of light c	unitless
	beta	beta particle
	gamma	Lorentz factor	unitless
	gamma	photon
	gamma	gamma ray
	gamma	shear strain	radian
	gamma	heat capacity ratio	unitless
	gamma	surface tension	newton per meter
	delta	change in a variable	unitless
	delta	Laplace operator	per square meter
	delta	displacement	meter
	delta	Dirac delta function
	delta	Kronecker delta
	epsilon	permittivity	farad per meter
	epsilon	strain	unitless
	epsilon nought	Vacuum permittivity	farad per meter
	zeta	damping ratio	unitless
	eta	angular jerk	radian per second cubed
	eta	energy efficiency	unitless
	eta	(dynamic) viscosity	pascal second
	theta	angular displacement	radian
	kappa	torsion coefficient also called torsion constant	newton meter per radian
	lambda	cosmological constant	per second squared
	lambda	wavelength	meter
	lambda	linear charge density	coulomb per meter
	lambda	eigenvalue	non-zero vector
	mu	magnetic moment	ampere square meter
	mu	coefficient of friction	unitless
	mu	(dynamic) viscosity	pascal second
	mu	permeability (electromagnetism)	henry per meter
	mu	reduced mass	kilogram
	mu	Standard gravitational parameter	cubic meter per second squared
	mu nought	Vacuum permeability or the magnetic constant	henry per meter
	nu	frequency	hertz
	nu	kinematic viscosity	meter squared per second
	nu	neutrino
	xi	electromotive force	volt
	pi	3.14159...	unitless
	rho	mass density usually simply called density	kilogram per cubic meter
	rho	volume charge density	coulomb per cubic meter
	rho	resistivity	ohm meter
	sigma	summation operator
	sigma	area charge density	coulomb per square meter
	sigma	electrical conductivity	siemens per meter
	sigma	normal stress	pascal
	sigma	scattering cross section	barn
	sigma	surface tension	newton per meter
	tau	torque	newton meter
	tau	shear stress	pascal
	tau	time constant	second
	tau	6.28318...	unitless
	phi	field strength	unit varies depending on context
	phi	magnetic flux	weber
	phi	electric potential	volt
	phi	Higgs field work function
	psi	wave function	m^−3/2
	omega	electric resistance	ohm
	omega	angular frequency	radian per second
	omega	angular velocity	radian per second