Physical Constants

Essential constants for physics and chemistry calculations

ConstantSymbolValueUnits
Speed of Light
Speed of light in vacuum
c2.998 × 10⁸m/s
Gravitational Constant
Universal gravitational constant
G6.674 × 10⁻¹¹N⋅m²/kg²
Planck's Constant
Quantum of action
h6.626 × 10⁻³⁴J⋅s
Reduced Planck's Constant
h/(2π)
1.055 × 10⁻³⁴J⋅s
Elementary Charge
Charge of a proton
e1.602 × 10⁻¹⁹C
Electron Mass
Rest mass of electron
mₑ9.109 × 10⁻³¹kg
Proton Mass
Rest mass of proton
mₚ1.673 × 10⁻²⁷kg
Neutron Mass
Rest mass of neutron
mₙ1.675 × 10⁻²⁷kg
Avogadro's Number
Number of particles in one mole
Nₐ6.022 × 10²³mol⁻¹
Gas Constant
Universal gas constant
R8.314J/(mol⋅K)
Boltzmann Constant
R/Nₐ, relates temperature to energy
k1.381 × 10⁻²³J/K
Stefan-Boltzmann Constant
Blackbody radiation constant
σ5.670 × 10⁻⁸W/(m²⋅K⁴)
Permittivity of Free Space
Electric constant
ε₀8.854 × 10⁻¹²F/m
Permeability of Free Space
Magnetic constant
μ₀1.257 × 10⁻⁶H/m
Coulomb's Constant
1/(4πε₀)
k8.988 × 10⁹N⋅m²/C²
Faraday Constant
Charge per mole of electrons
F9.648 × 10⁴C/mol
Rydberg Constant
Spectroscopic constant
R∞1.097 × 10⁷m⁻¹
Standard Gravity
Standard gravitational acceleration on Earth
g9.807m/s²
Standard Atmosphere
Standard atmospheric pressure
atm101,325Pa
Absolute Zero
Lowest possible temperature
0 K-273.15°C
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