Physical Constants

Physical constants
symbol	name	value		unit
c	speed of light in a vacuum	299,792,458		m/s
G	gravitational constant	6.67408	× 10⁻¹¹	N m²/kg²
h	planck constant	6.626070040 4.135667662	× 10⁻³⁴ × 10⁻¹⁵	J s eV s
hc		1.98644582 1239.84197	× 10⁻²⁵	J m eV nm
ℏ	h/2π reduced planck's constant dirac's constant	1.054571800 6.582119514	× 10⁻³⁴ × 10⁻¹⁶	J s eV s
ε₀	electric constant permitivitty of free space vacuum permitivitty	8.854187817	× 10⁻¹²	C²/N m²
μ₀	magnetic constant permeability of free space vacuum permeability	4π	× 10⁻⁷	T m/A
e	elementary charge	1.6021766208	× 10⁻¹⁹	C
m_e	electron mass	9.10938356 0.5109989461 0.000548579909070	× 10⁻³¹	kg MeV u
m_p	proton mass	1.672621898 938.2720813 1.007276466879	× 10⁻²⁷	kg MeV u
m_n	neutron mass	1.674927471 939.5654133 1.00866491588	× 10⁻²⁷	kg MeV u
m_u	atomic mass constant	1.660539040 931.4940954 1	× 10⁻²⁷	kg MeV u
N_A	avogadro's constant	6.022140857	× 10²³	1/mol
k	boltzmann's constant	1.38064852	× 10⁻²³	J/K
R	gas constant	8.3144598		J/mol K
σ	stefan-boltzmann constant	5.670367	× 10⁻⁸	W/m²K⁴
b	wien displacement constant	2.8977729 58.789238		mm/K GHz/K
g	standard gravity	9.80665		m/s²
atm	standard atmosphere	101,325		Pa
H₀	hubble constant*	69.3 2.25	× 10⁻¹⁸	km/s/Mpc s⁻¹