List of common physics notations

From Wikipedia, the free encyclopedia

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[edit]

Symbol Meaning SI unit of measure
magnetic vector potential tesla meter (T⋅m)
area square meters (m2)
amplitude meter
atomic mass number unitless
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 meters per second (m/s)
speed of sound meters 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)
diameter meter (m)
distance meter (m)
direction unitless
impact parameter meter (m)
differential (e.g. ) varied depending on context
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
electron unitless
elementary charge coulomb (C)
force newton (N)
Faraday constant coulombs per mole (C⋅mol−1)
frequency hertz (Hz)
friction newton (N)
electrical conductance siemens (S)
universal gravitational constant newton meter squared per kilogram squared (N⋅m2/kg2)
shear modulus pascal (Pa) or newton per square meter (N/m2)
acceleration due to gravity meters per second squared (m/s2), or equivalently, newtons per kilogram (N/kg)
magnetic field strength ampere per meter (A/m)
Hamiltonian joule (J)
enthalpy 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 unitless
electric current ampere (A)
Cartesian x-axis basis unit vector unitless
current density ampere per square meter (A/m2)
impulse kilogram meter per second (kg⋅m/s)
jerk meters per second cubed (m/s3)
imaginary unit (electrical) unitless
Cartesian y-axis basis unit vector unitless
kinetic energy joule (J)
wave vector radians per meter (m−1)
Boltzmann constant joule per kelvin (J/K)
wavenumber radians per meter (m−1)
stiffness newtons per meter (N⋅m−1)
Cartesian z-axis basis unit vector unitless
angular momentum newton meter second (N⋅m⋅s or kg⋅m2⋅s−1)
inductance henry (H)
luminosity watt (W)
Lagrangian joule (J)
length meter (m)
azimuthal quantum number unitless
magnetization amperes 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 reciprocal square meter (m−2)
radiancy meter per second
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)
displacement meter (m)
arc length meter (m)
distance meter (m)
period second (s)
temperature kelvin (K) or Celsius (C)
kinetic energy joule (J)
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)
specific energy joule per kilogram (J/kg)
also called electric potential difference
volt (V)
volume cubic meter (m3)
shear force
velocity meter per second (m/s)
weight newton (N)
mechanical work joule (J)
width meter (m)
electrical reactance ohm (Ω)
position vector meter (m)
displacement meter (m)
a generic unknown varied depending on context
admittance siemens (S)
compressibility factor unitless
electrical impedance ohm (Ω)
impedance of free space ohm (Ω)

Greek characters[edit]

Symbol Name Meaning SI unit of measure
alpha alpha particle
angular acceleration radian per second squared (rad/s2)
fine-structure constant unitless
beta velocity in terms of the speed of light c unitless
beta particle
gamma Lorentz factor unitless
gamma ray
shear strain radian
heat capacity ratio unitless
surface tension newton per meter (N/m)
delta change in a variable (e.g. ) unitless
Laplace operator per square meter (m−2)
displacement (usually small) meter (m)
Dirac delta function
Kronecker delta (e.g )
epsilon permittivity farad per meter (F/m)
strain unitless
epsilon nought vacuum permittivity constant farad per meter (F/m)
zeta damping ratio unitless
eta angular jerk radians per second cubed (rad⋅s−3)
energy efficiency unitless
(dynamic) viscosity (also ) pascal second (Pa⋅s)
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)
linear charge density coulomb per meter (C/m)
eigenvalue non-zero vector
mu magnetic moment ampere square meter (A⋅m2)
coefficient of friction unitless
(dynamic) viscosity (also ) pascal second (Pa⋅s)
permeability (electromagnetism) henry per meter (H/m)
reduced mass kilogram (kg)
gravitational parameter cubic meter per second squared
mu nought vacuum permeability constant or magnetic constant henry per meter (H/m)
nu frequency hertz (Hz)
kinematic viscosity meters squared per second (m2/s)
xi electromotive force volt (V)
pi 3.14159... (irrational number) unitless
rho mass density
usually simply called density
kilogram per cubic meter (kg/m3)
volume charge density coulomb per cubic meter (C/m3)
resistivity ohm meter (Ω⋅m)
sigma summation operator
area charge density coulomb per square meter (C/m2)
electrical conductivity siemens per meter (S/m)
normal stress pascal (Pa)
scattering cross section barn (10^-28 m^2)
surface tension newton per meter (N/m)
tau torque newton meter (N⋅m)
shear stress pascal (Pa)
time constant second (s)
6.28318... () unitless
phi field strength unit varies depending on context
magnetic flux weber (Wb)
electric potential volt (V)
Higgs field work function
psi wave function m−3/2
omega electric resistance ohm
angular frequency radian per second (rad/s)

Other characters[edit]

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)
"der", "dow", "die", "partial" or simply "d" partial derivative (e.g. )
D'Alembert operator
angle brackets average

sometimes over Maxwell–Boltzmann distribution

Dirac notation


See also[edit]



  1. ^ Elert, Glenn. "Special Symbols". The Physics Hypertextbook. Glenn Elert. Retrieved 4 August 2021.
  2. ^ NIST (4 August 2021). "International SI System of Units". NIST.