# Table of physical constants

(Redirected from Table of Physical Constants)

## Table of universal constants

Quantity Symbol Value Relative Standard Uncertainty
characteristic impedance of vacuum ${\displaystyle Z_{0}=\mu _{0}c\,}$  376.730 313 461... Ω defined
electric constant (permittivity of free space) ${\displaystyle \varepsilon _{0}=1/(\mu _{0}c^{2})\,}$  8.854 187 817... × 10-12F·m-1 defined
magnetic constant (permeability of free space) ${\displaystyle \mu _{0}\,}$  4π × 10-7 N·A-2 = 1.2566 370 614... × 10-6 N·A-2 defined
gravitational constant (Newtonian constant of gravitation) ${\displaystyle G\,}$  6.6742(10) × 10-11m3·kg-1·s-2 1.5 × 10-4
Planck's constant ${\displaystyle h\,}$  6.626 0693(11) × 10-34 J·s 1.7 × 10-7
Dirac's constant ${\displaystyle \hbar =h/(2\pi )}$  1.054 571 68(18) × 10-34 J·s 1.7 × 10-7
speed of light in vacuum ${\displaystyle c\,}$  299 792 458 m·s-1 defined

## Table of electromagnetic constants

Quantity Symbol Value1 (SI units) Relative Standard Uncertainty
Bohr magneton ${\displaystyle \mu _{B}=e\hbar /2m_{e}}$  927.400 949(80) × 10-26 J·T-1 8.6 × 10-8
conductance quantum ${\displaystyle G_{0}=2e^{2}/h\,}$  7.748 091 733(26) × 10-5 S 3.3 × 10-9
Coulomb's constant ${\displaystyle \kappa =1/4\pi \varepsilon _{0}\,}$  8.987 742 438 × 109 N·m2C-2 defined
elementary charge ${\displaystyle e\,}$  1.602 176 53(14) × 10-19 C 8.5 × 10-8
Josephson constant ${\displaystyle K_{J}=2e/h\,}$  483 597.879(41) × 109 Hz· V-1 8.5 × 10-8
magnetic flux quantum ${\displaystyle \phi _{0}=h/2e\,}$  2.067 833 72(18) × 10-15 Wb 8.5 × 10-8
nuclear magneton ${\displaystyle \mu _{N}=e\hbar /2m_{p}}$  5.050 783 43(43) × 10-27 J·T-1 8.6 × 10-8
resistance quantum ${\displaystyle R_{0}=h/2e^{2}\,}$  12 906.403 725(43) Ω 3.3 × 10-9
von Klitzing constant ${\displaystyle R_{K}=h/e^{2}\,}$  25 812.807 449(86) Ω 3.3 × 10-9

## Table of atomic and nuclear constants

 Quantity Symbol Value1 (SI units) Relative Standard Uncertainty Bohr radius ${\displaystyle a_{0}=\alpha /4\pi R_{\infty }\,}$ 0.529 177 2108(18) × 10-10 m 3.3 × 10-9 Fermi coupling constant ${\displaystyle G_{F}/(\hbar c)^{3}}$ 1.166 39(1) × 10-5 GeV-2 8.6 × 10-6 fine structure constant ${\displaystyle \alpha =\mu _{0}e^{2}c/(2h)=e^{2}/(4\pi \varepsilon _{0}\hbar c)\,}$ 7.297 352 568(24) × 10-3 3.3 × 10-9 Hartree energy ${\displaystyle E_{h}=2R_{\infty }hc\,}$ 4.359 744 17(75) × 10-18 J 1.7 × 10-7 quantum of circulation ${\displaystyle h/2m_{e}\,}$ 3.636 947 550(24) × 10-4 m2 s-1 6.7 × 10-9 Rydberg constant ${\displaystyle R_{\infty }=\alpha ^{2}m_{e}c/2h\,}$ 10 973 731.568 525(73) m-1 6.6 × 10-12 Thomson cross section ${\displaystyle (8\pi /3)r_{e}^{2}}$ 0.665 245 873(13) × 10-28 m2 2.0 × 10-8 Weinberg angle|weak mixing angle ${\displaystyle \sin ^{2}\theta _{W}=1-(m_{W}/m_{Z})^{2}\,}$ 0.222 15(76) 3.4 × 10-3

## Table of physico-chemical constants

 Quantity Symbol Value1 (SI units) Relative Standard Uncertainty atomic mass constant (unified atomic mass unit) ${\displaystyle m_{u}=1\ u\,}$ 1.660 538 86(28) × 10-27 kg 1.7 × 10-7 Avogadro's number ${\displaystyle N_{A},L\,}$ 6.0221417(10) × 1023 1.7 × 10-7 Boltzmann constant ${\displaystyle k=R/N_{A}\,}$ 1.380 6505(24) × 10-23 J·K-1 1.8 × 10-6 Faraday constant ${\displaystyle F=N_{A}e\,}$ 96 485.3383(83)C·mol-1 8.6 × 10-8 first radiation constant ${\displaystyle c_{1}=2\pi hc^{2}\,}$ 3.741 771 38(64) × 10-16 W·m2 1.7 × 10-7 for spectral radiance ${\displaystyle c_{1L}\,}$ 1.191 042 82(20) × 10-16 W · m2 sr-1 1.7 × 10-7 Loschmidt constant at ${\displaystyle T}$ =273.15 K and ${\displaystyle p}$ =101.325 kPa ${\displaystyle n_{0}=N_{A}/V_{m}\,}$ 2.686 7773(47) × 1025 m-3 1.8 × 10-6 gas constant ${\displaystyle R\,}$ 8.314 472(15) J·K-1·mol-1 1.7 × 10-6 molar Planck constant ${\displaystyle N_{A}h\,}$ 3.990 312 716(27) × 10-10 J · s · mol-1 6.7 × 10-9 molar volume of an ideal gas at ${\displaystyle T}$ =273.15 K and ${\displaystyle p}$ =100 kPa ${\displaystyle V_{m}=RT/p\,}$ 22.710 981(40) × 10-3 m3 ·mol-1 1.7 × 10-6 at ${\displaystyle T}$ =273.15 K and ${\displaystyle p}$ =101.325 kPa 22.413 996(39) × 10-3 m3 ·mol-1 1.7 × 10-6 Sackur-Tetrode constant at ${\displaystyle T}$ =1 K and ${\displaystyle p}$ =100 kPa ${\displaystyle S_{0}/R={\frac {5}{2}}}$  ${\displaystyle +\ln \left[(2\pi m_{u}kT/h^{2})^{3/2}kT/p\right]}$ -1.151 7047(44) 3.8 × 10-6 at ${\displaystyle T}$ =1 K and ${\displaystyle p}$ =101.325 kPa -1.164 8677(44) 3.8 × 10-6 second radiation constant ${\displaystyle c_{2}=hc/k\,}$ 1.438 7752(25) × 10-2 m·K 1.7 × 10-6 Stefan-Boltzmann constant ${\displaystyle \sigma =(\pi ^{2}/60)k^{4}/\hbar ^{3}c^{2}}$ 5.670 400(40) × 10-8 W·m-2·K-4 7.0 × 10-6 Wien displacement law constant ${\displaystyle b=(hc/k)/\,}$  4.965 114 231... 2.897 7685(51) × 10-3 m · K 1.7 × 10-6

 Quantity Symbol Value (SI units) Relative Standard Uncertainty conventional value of Josephson constant2 ${\displaystyle K_{J-90}\,}$ 483 597.9 × 109 Hz · V-1 defined conventional value of von Klitzing constant3 ${\displaystyle R_{K-90}\,}$ 25 812.807 Ω defined molar mass constant ${\displaystyle M_{u}=M(\,^{12}{\mbox{C}})/12}$ 1 × 10-3 kg · mol-1 defined of carbon-12 ${\displaystyle M(\,^{12}{\mbox{C}})=N_{A}m(\,^{12}{\mbox{C}})}$ 12 × 10-3 kg · mol−1 defined standard acceleration of gravity (free fall on Earth) ${\displaystyle g_{n}\,\!}$ 9.806 65 m·s-2 defined standard atmosphere ${\displaystyle {\mbox{atm}}\,}$ 101 325 Pa defined