Table of Physical Constants

Need a value for a fundamental physical constant? Typically, these values are learned only on the short term as you are introduced to them and forgotten as soon as the test or task is finished. When they are needed again, constant searching through the textbook is one way to find the information again. A better way would be to us this handy reference table.

Constant	Symbol	Value
acceleration due to gravity	g	9.8 m s-2
atomic mass unit	amu, mu or u	1.66 x10-27 kg
Avogadro's Number	N	6.022 x 1023 mol-1
Bohr radius	a0	0.529 x 10-10 m
Boltzmann constant	k	1.38 x 10-23 J K-1
electron charge to mass ratio	-e/me	-1.7588 x 1011 C kg-1
electron classical radius	re	2.818 x 10-15 m
electron mass energy (J)	mec2	8.187 x 10-14 J
electron mass energy (MeV)	mec2	0.511 MeV
electron rest mass	me	9.109 x 10-31 kg
Faraday constant	F	9.649 x 104 C mol-1
fine-structure constant	α	7.297 x 10-3
gas constant	R	8.314 J mol-1 K-1
gravitational constant	G	6.67 x 10-11 Nm2kg-2
neutron mass energy (J)	mnc2	1.505 x 10-10 J
neutron mass energy (MeV)	mnc2	939.565 MeV
neutron rest mass	mn	1.675 x 10-27 kg
neutron-electron mass ratio	mn/me	1838.68
neutron-proton mass ratio	mn/mp	1.0014
permeability of a vacuum	μ0	4π x 10-7 N A-2
permittivity of a vacuum	ε0	8.854 x 10-12 F m-1
Planck constant	h	6.626 x 10-34 J s
proton mass energy (J)	mpc2	1.503 x 10-10 J
proton mass energy (MeV)	mpc2	938.272 MeV
proton rest mass	mp	1.6726 x 10-27 kg
proton-electron mass ratio	mp/me	1836.15
Rydberg constant	r∞	1.0974 x 107 m-1
speed of light in vacuum	C	2.9979 x 108 m/s