| Symbol |
Meaning |
| A |
area |
| a |
acceleration |
| B |
magnetic field |
| C |
capacitance, heat capacity |
| c |
speed of light (in a vacuum), speed of sound, specific
heat capacity |
| D |
electric displacement |
| d |
distance, diameter, differential (e.g. dx) |
| E |
energy, electric field |
| F |
force |
| f |
friction, frequency, function |
| G |
gravitational constant |
| g |
acceleration due to gravity |
| H |
magnetic field |
| h |
height, Planck constant |
 |
reduced Planck constant |
| I |
electric current, sound intensity, moment of inertia |
| i |
imaginary unit |
| J |
current density |
| k |
Boltzmann constant, thermal conductivity |
| L |
angular momentum, inductance |
| l |
length |
| M |
moment of force |
| m |
mass |
| n |
refractive index |
| P |
power, pressure |
| p |
momentum |
| Q |
electric charge, heat |
| R |
electrical resistance |
| r |
radius, radius vector (position) |
| S |
surface area, entropy, action |
| s |
displacement |
| T |
temperature, period |
| t |
time |
| U |
internal energy, potential energy |
| V |
volume, voltage, shear force |
| v |
velocity |
| W |
mechanical work |
| w |
width |
| x |
a generic unknown, displacement |
| γ |
(Gamma) Lorentz factor, photon, gamma ray |
| Δ |
(Delta) a change in a variable (e.g. Δx) |
| δ |
(Delta) displacement (usually small) |
| ε |
(Epsilon) strain |
| ζ |
(Zeta) damping ratio |
| η |
(Eta) energy efficiency |
| θ |
(Theta) angle |
| λ |
(Lambda) wavelength |
| μ |
(Mu) coefficient of friction, dynamic viscosity, permeability (electromagnetism) |
| ν |
(Nu) kinematic viscosity |
| π |
(Pi) 3.14159... |
| ρ |
(Rho) resistivity, density, charge density |
| Σ |
(Sigma) summation operator |
| σ |
(Sigma) electrical conductivity, normal stress |
| τ |
(Tau) torque, shear stress, time constant |
| Φ |
(Phi) magnetic flux |
| φ |
(Phi) electric potential |
| Ω |
(Omega) ohm |
| ω |
(Omega) angular frequency |