Commonly Used Physical Constants

Uncertainty should be read as 1.234(56) = 1.234 $\pm$ 0.056
Name	Symbol	Value	Units	Relative Uncertainty
Speed of light (in vacuum)	$c$	$299\ 792\ 458$	$\mathrm {m} \ \mathrm {s} ^{-1}$	(exact)
Magnetic Constant	$\mu _{0}$	$4\pi \times 10^{-7}\approx 12.566\ 370\ 6\times 10^{-7}$	$\mathrm {N} \ \mathrm {A} ^{-2}$	(exact)
Electric Constant	$\varepsilon _{0}=1/\left(\mu _{0}c^{2}\right)$	$\approx 8.854\ 187\ 817\times 10^{-12}$	$\mathrm {F} \ \mathrm {m} ^{-1}$	(exact)
Newtonian Gravitaional Constant	$G$	$6.674\ 2(10)\times 10^{-11}$	$\mathrm {m} ^{3}\ \mathrm {kg} ^{-1}\ \mathrm {s} ^{-2}$	$1.5\times 10^{-4}$
Plank's Constant	$h$	$6.626\ 069\ 3(11)\times 10^{-34}$	$\mathrm {J} \ \mathrm {s}$	$1.7\times 10^{-7}$
Elementary charge	$e$	$1.602\ 176\ 53(14)\times 10^{-19}$	$\mathrm {C}$	$8.5\times 10^{-8}$
Mass of the electron	$m_{e}$	$9.109\ 382\ 6(16)\times 10^{-31}$	$\mathrm {kg}$	$1.7\times 10^{-7}$
Mass of the proton	$m_{p}$	$1.672\ 621\ 71(29)\times 10^{-27}$	$\mathrm {kg}$	$1.7\times 10^{-7}$
Fine structure constant	$\alpha ={\frac {e^{2}}{4\pi \varepsilon _{0}\hbar c}}$	$7.297\ 352\ 568(24)\times 10^{-3}$	dimensionless	$3.3\times 10^{-9}$
Molar gass constant	$R$	$8.314\ 472(15)$	$\mathrm {J} \ \mathrm {mol} ^{-1}\ \mathrm {K} ^{-1}$	$1.7\times 10^{-6}$
Boltzmann's constant	$k$	$1.380\ 650\ 5(24)\times 10^{-23}$	$\mathrm {J} \ \mathrm {K} ^{-1}$	$1.8\times 10^{-6}$
Avogadro's Number	$N_{\text{A}},L$	$6.022\ 141\ 5(10)\times 10^{23}$	$\mathrm {mol} ^{-1}$	$1.7\times 10^{-7}$
Rydberg constant	$R_{\infty }$	$10\ 973\ 731.568\ 525(73)$	$\mathrm {m} ^{-1}$	$6.6\times 10^{-12}$
Standard acceleration of gravity	$g$	$9.806\ 65$	$\mathrm {m} \ \mathrm {s} ^{-2}$	defined
Atmospheric pressure	$\mathrm {atm}$	$101\ 325$	$\mathrm {Pa}$	defined
Bohr Radius	$a_{0}\$	$0.529\ 177\ 208\ 59(36)\times 10^{-10}\$	$\mathrm {m} \$	$6.8\times 10^{-10}$
Electron Volt	$eV$	$1.602\ 176\ 53(14)\times 10^{-19}$	$\mathrm {J}$	$8.7\times 10^{-8}$
Luminous efficacy of monochromatic radiation	$K_{cd}$	$683$	$\mathrm {lm/W}$	(exact)
hyperfine transition frequency of Cs-133	$\Delta \nu _{\text{Cs}}$	$9\ 192\ 631\ 770$	$\mathrm {Hz}$	(exact)
Reduced Planck constant	$\hbar =h/2\pi$	$1.054\ 571\ 817\times {10}^{-34}$	$\mathrm {J} \cdot \mathrm {s}$	(exact)
atomic mass of Carbon 12	$m({}^{12}{\text{C}})$	$1.992\ 646\ 879\ 92(60)\times {10}^{-26}$	$\mathrm {kg}$
molar mass of Carbon-12	$M({}^{12}{\text{C}})=N_{\text{A}}m({}^{12}{\text{C}})$	$11.999\ 999\ 9958(36)\times {10}^{-3}$	$\mathrm {kg\cdot {mol}^{-1}}$
atomic mass constant	$m_{\text{u}}=m({}^{12}{\text{C}})/12=1\,{\text{Da}}$	$1.660\ 539\ 066\ 60(50)\times {10}^{-27}$	$\mathrm {kg}$
molar mass constant	$M_{\text{u}}=M({}^{12}{\text{C}})/12=N_{\text{A}}m_{\text{u}}$	$0.999\ 999\ 999\ 65(30)\times {10}^{-3}$	$\mathrm {kg\cdot {mol}^{-1}}$
molar volume of silicon	$V_{m}(\mathrm {Si} )$	$1.205\ 883\ 199(60)\times {10}^{-5}$	$\mathrm {m^{3}\cdot {mol}^{-1}}$
molar Planck constant	$N_{\text{A}}h$	$3.990\ 312\ 712\ldots {10}^{-10}$	$\mathrm {J\cdot {Hz}^{-1}\cdot {mol}^{-1}}$
Stefan-Boltzmann constant	$\sigma =\pi ^{2}k_{B}^{4}/60\hbar ^{3}c^{2}$	$5.670\ 374\ 419\ldots \times {10}^{-8}$	$\mathrm {W\cdot m^{-2}\cdot K^{-4}}$
first radiation constant	$c_{1}=2\pi hc^{2}$	$3.741\ 771\ 852\ldots {10}^{-16}$	$\mathrm {W\cdot m^{2}}$
first radiation constant for spectral radiance	$c_{\text{1L}}=2hc^{2}/sr$ ^[1]	$1.191\ 042\ 972\ 397\ 188\ 414\ 079\ 4892\times {10}^{-16}$	$\mathrm {W\cdot m^{2}{sr}^{-1}}$
second radiation constant	$c_{2}=hc/k_{B}$	$1.438\ 776\ 877\ldots \times {10}^{-2}$	$\mathrm {m\cdot K}$
Wien wavelength displacement constant	$b$	$2.897\ 771\ 955\ldots \times {10}^{-3}$	$\mathrm {m\cdot K}$
Wien frequency displacement constant	$b'=c/b$	$5.878\ 925\ 757\ \times {10}^{10}$	$\mathrm {Hz\cdot K^{-1}}$
Wien entropy displacement constant	$b_{\text{entropy}}$	$3.002\ 916\ 077\ldots \times {10}^{-3}$	$\mathrm {m\cdot K}$
Faraday constant	$F=N_{\text{A}}e$ ^[2]	$96\ 485.332\ 123\ 310\ 0184$	$\mathrm {C\cdot {mol}^{-1}}$