Fundamental Physical Constants --- CODATA 2013 Listing

Quantity Symbol Value Unit
alpha particle-electron mass ratio 7294.299 5365(31)
alpha particle mass 6.644 656 20(33) x 10-27 kg
alpha particle mass energy equivalent 5.971 919 17(30) x 10-10 J
alpha particle mass energy equivalent in MeV 3727.379 109(93) MeV
alpha particle mass in u 4.001 506 179 127(62) u
alpha particle molar mass 4.001 506 179 127(62) x 10-3 kg mol-1
alpha particle-proton mass ratio 3.972 599 689 51(41)
Angstrom star 1.000 014 98(90) x 10-10 m
atomic mass constant 1.660 538 782(83) x 10-27 kg
atomic mass constant energy equivalent 1.492 417 830(74) x 10-10 J
atomic mass constant energy equivalent in MeV 931.494 028(23) MeV
atomic mass unit-electron volt relationship 931.494 028(23) x 106 eV
atomic unit of mass 9.109 382 15(45) x 10-31 kg
atomic mass unit-kilogram relationship 1.660 538 782(83) x 10-27 kg
atomic unit of action ( Dirac's Constant ) 1.054 571 628(53) x 10-34 J s
atomic unit of charge ( elementary charge ) 1.602 176 487(40) x 10-19 C
atomic unit of charge density 1.081 202 300(27) x 1012 C m-3
atomic unit of current 6.623 617 63(17) x 10-3 A
atomic unit of electric dipole moment 8.478 352 81(21) x 10-30 C m
atomic unit of electric field 5.142 206 32(13) x 1011 V m-1
atomic unit of electric field gradient 9.717 361 66(24) x 1021 V m-2
atomic unit of electric polarizablity 1.648 777 2536(34) x 10-41 C2 m2 J-1
atomic unit of electric potential 27.211 383 86(68) V
atomic unit of electric quadrupole moment 4.486 551 07(11) x 10-40 C m2
atomic unit of energy 4.359 743 94(22) x 10-18 J
atomic unit of force 8.238 722 06(41) x 10-8 N
atomic unit of length 0.529 177 208 59(36) x 10-10 m
atomic unit of mass 9.109 382 15(45) x 10-31 kg
atomic unit of momentum 1.992 851 565(99) x 10-24 kg m s-1
atomic unit of permittivity 1.112 650 056... x 10-10 F m-1
atomic unit of time 2.418 884 326 505(16) x 10-17 s
atomic unit of velocity 2.187 691 2541(15) x 106 m s-1
Avogadro constant, number 6.022 141 79(30) x 1023 mol-1
Bohr magneton 927.400 915(23) x 10-26 J T-1
Bohr magneton in eV/T 5.788 381 7555(79) x 10-5 eV T-1
Bohr magneton in Hz/T 13.996 246 04(35) x 109 Hz T-1
Bohr magneton in inverse meters per tesla 46.686 4515(12) m-1 T-1
Bohr magneton in K/T 0.671 7131(12) K T-1
Bohr radius 0.529 177 208 59(36) x 10-10 m
Boltzmann 1.380 6504(24) x 10-23 J K-1
Boltzmann constant in eV/K 8.617 343(15) x 10-5 eV K-1
Boltzmann constant in Hz/K 2.083 6644(36) x 1010 Hz K-1
Boltzmann constant in inverse meters per kelvin 69.503 56(12) m-1 K-1
characteristic impedance of vacuum 376.730 313 461... Ω
classical electron radius 2.817 940 2894(58) x 10-15 m
Coulomb ( force ) constant 8.987 551 787 4 x 109 N m2 C-2
Compton wavelength 2.426 310 2175(33) x 10-12 m
Compton wavelength over 2 pi 386.159 264 59(53) x 10-15 m
conductance quantum 7.748 091 7004(53) x 10-5 S
deuteron-electron magnetic moment ratio -4.664 345 537(39) x 10-4
deuteron-electron mass ratio 3670.482 9654(16)
deuteron g factor 0.857 438 2308(72)
deuteron mass 3.343 583 20(17) x 10-27 kg
deuteron mass energy equivalent 3.005 062 72(15) x 10-10 J
deuteron mass energy equivalent in MeV 1875.612 793(47) MeV
deuteron mass in u 2.013 553 212 724(78) u
deuteron molar mass 2.013 553 212 724(78) x 10-3 kg mol-1
deuteron-electron magnetic moment ratio -4.664 345 537(39) x 10-4
deuteron-neutron magnetic moment ratio -0.448 206 52(11)
deuteron-proton magnetic moment ratio 0.307 012 2070(24)
deuteron-proton mass ratio 1.999 007 501 08(22)
Dirac's Constant 1.054 571 628(53) x 10-34 J s
electric constant ( vacuum permittivity ) 8.854 187 817... x 10-12 F m-1
electron charge to mass quotient -1.758 820 150(44) x 1011 C kg-1
electron-deuteron magnetic moment ratio -2143.923 498(18)
electron-deuteron mass ratio 2.724 437 1093(12) x 10-4
electron g factor -2.002 319 304 3622(15)
electron mass 9.109 382 15(45) x 10-31 kg
electron mass energy equivalent 8.187 104 38(41) x 10-14 J
electron mass energy equivalent in MeV 0.510 998 910(13) MeV
electron mass in u 5.485 799 0943(23) x 10-4 u
electron molar mass 5.485 799 0943(23) x 10-7 kg mol-1
electron-muon magnetic moment ratio 206.766 9877(52)
electron-muon mass ratio 4.836 331 71(12) x 10-3
electron-neutron magnetic moment ratio 960.920 50(23)
electron-neutron mass ratio 5.438 673 4459(33) x 10-4
electron-proton magnetic moment ratio -658.210 6848(54)
electron-proton mass ratio 5.446 170 2177(24) x 10-4
electron-tau mass ratio 2.875 64(47) x 10-4
electron to alpha particle mass ratio 1.370 933 555 70(58) x 10-4
electron volt 1.602 176 487(40) x 10-19 J
electron volt-atomic mass unit relationship 1.073 544 188(27) x 10-9 u
electron volt-hartree relationship 3.674 932 540(92) x 10-2 Eh
electron volt-hertz relationship 2.417 989 454(60) x 1014 Hz
electron volt-inverse meter relationship 8.065 544 65(20) x 105 m-1
electron volt-joule relationship 1.602 176 487(40) x 10-19 J
electron volt-kelvin relationship 1.160 4505(20) x 104 K
electron volt-kilogram relationship 1.782 661 758(44) x 10-36 kg
elementary charge 1.602 176 487(40) x 10-19 C
elementary charge over h 2.417 989 454(60) x 1014 A J-1
Faraday constant 96 485.3399(24) C mol-1
Faraday constant for conventional electric current 96 485.3401(48) C90 mol-1
Fermi coupling constant 1.166 37(1) x 10-5 GeV-2
fine-structure constant 7.297 352 5376(50) x 10-3
helion-electron mass ratio 5495.885 2765(52)
helion mass 5.006 411 92(25) x 10-27 kg
helion mass energy equivalent 4.499 538 64(22) x 10-10 J
helion mass energy equivalent in MeV 2808.391 383(70) MeV
helion mass in u 3.014 932 2473(26) u
helion molar mass 3.014 932 2473(26) x 10-3 kg mol-1
helion-proton mass ratio 2.993 152 6713(26)
hertz-atomic mass unit relationship 4.439 821 6294(64) x 10-24 u
hertz-electron volt relationship 4.135 667 33(10) x 10-15 eV
hertz-hartree relationship 1.519 829 846 006(10) x 10-16 Eh
hertz-inverse meter relationship 3.335 640 951ldots x 10-9 m-1
hertz-joule relationship 6.626 068 96(33) x 10-34 J
hertz-kelvin relationship 4.799 2374(84) x 10-11 K
hertz-kilogram relationship 7.372 496 00(37) x 10-51 kg
inverse fine-structure constant 137.035 999 679(94)
inverse meter-atomic mass unit relationship 1.331 025 0394(19) x 10-15 u
inverse meter-electron volt relationship 1.239 841 875(31) x 10-6 eV
inverse meter-hartree relationship 4.556 335 252 760(30) x 10-8 Eh
inverse meter-hertz relationship 299 792 458 Hz
inverse meter-joule relationship 1.986 445 501(99) x 10-25 J
inverse meter-kelvin relationship 1.438 7752(25) x 10-2 K
inverse meter-kilogram relationship 2.210 218 70(11) x 10-42 kg
inverse of conductance quantum 12 906.403 7787(88) Ω
joule-atomic mass unit relationship 6.700 536 41(33) x 109 u
joule-electron volt relationship 6.241 509 65(16) x 1018 eV
joule-hartree relationship 2.293 712 69(11) x 1017 Eh
joule-hertz relationship 1.509 190 450(75) x 1033 Hz
joule-inverse meter relationship 5.034 117 47(25) x 1024 m-1
joule-kelvin relationship 7.242 963(13) x 1022 K
joule-kilogram relationship 1.112 650 056l ...  x 10-17 kg
kelvin-atomic mass unit relationship 9.251 098(16) x 10-14 u
kelvin-electron volt relationship 8.617 343(15) x 10-5 eV
kelvin-hartree relationship 3.166 8153(55) x 10-6 Eh
kelvin-hertz relationship 2.083 6644(36) x 1010 Hz
kelvin-inverse meter relationship 69.503 56(12) m-1
kelvin-joule relationship 1.380 6504(24) x 10-23 J
kelvin-kilogram relationship 1.536 1807(27) x 10-40 kg
kilogram-atomic mass unit relationship 6.022 141 79(30) x 1026 u
kilogram-electron volt relationship 5.609 589 12(14) x 1035 eV
kilogram-hartree relationship 2.061 486 16(10) x 1034 Eh
kilogram-hertz relationship 1.356 392 733(68) x 1050 Hz
kilogram-inverse meter relationship 4.524 439 15(23) x 1041 m-1
kilogram-joule relationship 8.987 551 787l ... x 1016 J
kilogram-kelvin relationship 6.509 651(11) x 1039 K
magnetic constant ( vacuum permeability ) 4π x 10-7
= 1.256 637 061... x 10-6
N A-2
muon Compton wavelength 11.734 441 04(30) x 10-15 m
muon Compton wavelength over 2 pi 1.867 594 295(47) x 10-15 m
muon-electron mass ratio 206.768 2823(52)
muon-neutron mass ratio 0.112 454 5167(29)
muon g factor -2.002 331 8414(12)
muon mass 1.883 531 30(11) x 10-28 kg
muon mass energy equivalent 1.692 833 510(95) x 10-11 J
muon mass energy equivalent in MeV 105.658 3668(38) MeV
muon mass in u 0.113 428 9256(29) u
muon molar mass 0.113 428 9256(29) x 10-3 kg mol-1
muon-proton magnetic moment ratio -3.183 345 137(85)
muon-proton mass ratio 0.112 609 5261(29)
muon-tau mass ratio 5.945 92(97) x 10-2
natural unit of action 1.054 571 628(53) x 10-34 J s
natural unit of action in eV s 6.582 118 99(16) x 10-16 eV s
natural unit of energy 8.187 104 38(41) x 10-14 J
natural unit of energy in MeV 0.510 998 910(13) MeV
natural unit of length 386.159 264 59(53) x 10-15 m
natural unit of mass 9.109 382 15(45) x 10-31 kg
natural unit of momentum 2.730 924 06(14) x 10-22 kg m s-1
natural unit of momentum in MeV/c 0.510 998 910(13) MeV/c
natural unit of time 1.288 088 6570(18) x 10-21 s
natural unit of velocity 299 792 458 m s-1
neutron Compton wavelength 1.319 590 8951(20) x 10-15 m
neutron Compton wavelength over 2 pi 0.210 019 413 82(31) x 10-15 m
neutron-electron mass ratio 1838.683 6605(11)
neutron g factor -3.826 085 45(90)
neutron mass 1.674 927 211(84) x 10-27 kg
neutron mass energy equivalent 1.505 349 505(75) x 10-10 J
neutron mass energy equivalent in MeV 939.565 346(23) MeV
neutron mass in u 1.008 664 915 97(43) u
neutron molar mass 1.008 664 915 97(43) x 10-3 kg mol-1
neutron-muon mass ratio 8.892 484 09(23)
neutron-electron magnetic moment ration 1.040 668 82(25) x 10-3
neutron-proton magnetic moment ratio -0.684 979 34(16)
neutron-proton mass ratio 1.001 378 419 18(46)
neutron-tau mass ratio 0.528 740(86)
Newtonian constant of gravitation 6.67428(67) x 10-11 m3 kg-1 s-2
Newtonian constant of gravitation over h-bar c 6.708 81(67) x 10-39 (GeV/c2)-2
nuclear magneton 5.050 783 24(13) x 10-27 J T-1
nuclear magneton in eV/T 3.152 451 2326(45) x 10-8 eV T-1
nuclear magneton in inverse meters per tesla 2.542 623 616(64) x 10-2 m-1 T-1
nuclear magneton in K/T 3.658 2637(64) x 10-4 K T-1
nuclear magneton in MHz/T 7.622 593 84(19) MHz T-1
Planck's constant 6.626 068 96(33) x 10-34 J s
Planck's constant in eV s 4.135 667 33(10) x 10-15 eV s
Planck's constant over 2 pi ( Dirac's Constant ) 1.054 571 628(53) x 10-34 J s
Planck's constant over 2 pi in eV s 6.582 118 99(16) x 10-16 eV s
Planck's constant over 2 pi times c in MeV fm 197.326 9631(49) MeV fm
Planck length 1.616 252(81) x 10-35 m
Planck mass 2.176 44(11) x 10-8 kg
Planck mass energy equivalent in GeV 1.220 892(61) x 1019 GeV
Planck temperature 1.416 785(71) x 1032 K
Planck time 5.391 24(27) x 10-44 s
proton charge to mass quotient 9.578 833 92(24) x 107 C kg-1
proton Compton wavelength 1.321 409 8446(19) x 10-15 m
proton Compton wavelength over 2 pi 0.210 308 908 61(30) x 10-15 m
proton-electron mass ratio 1836.152 672 47(80)
proton g factor 5.585 694 713(46)
proton mass 1.672 621 637(83) x 10-27 kg
proton mass energy equivalent 1.503 277 359(75) x 10-10 J
proton mass energy equivalent in MeV 938.272 013(23) MeV
proton mass in u 1.007 276 466 77(10) u
proton molar mass 1.007 276 466 77(10) x 10-3 kg mol-1
proton-muon mass ratio 8.880 243 39(23)
proton-neutron magnetic moment ratio -1.459 898 06(34)
proton-neutron mass ratio 0.998 623 478 24(46)
proton-tau mass ratio 0.528 012(86)
quantum of circulation 3.636 947 5199(50) x 10-4 m2 s-1
speed of light in vacuo ( vacuum ) 299 792 458 m s-1
standard acceleration of gravity earth's surface at sea level 9.806 65 m s-2
standard atmosphere 101 325 Pa
Stefan-Boltzmann constant 5.670 400(40) x 10-8 W m-2 K-4
tau Compton wavelength 0.697 72(11) x 10-15 m
tau Compton wavelength over 2 pi 0.111 046(18) x 10-15 m
tau-electron mass ratio 3477.48(57)
tau mass 3.167 77(52) x 10-27 kg
tau mass energy equivalent 2.847 05(46) x 10-10 J
tau mass energy equivalent in MeV 1776.99(29) MeV
tau mass in u 1.907 68(31) u
tau molar mass 1.907 68(31) x 10-3 kg mol-1
tau-muon mass ratio 16.8183(27)
tau-neutron mass ratio 1.891 29(31)
tau-proton mass ratio 1.893 90(31)
triton-electron magnetic moment ratio -1.620 514 423(21) x 10-3
triton-neutron magnetic moment ratio -1.557 185 53(37)
triton-electron mass ratio 5496.921 5269(51)
triton g factor 5.957 924 896(76)
triton mass 5.007 355 88(25) x 10-27 kg
triton mass energy equivalent 4.500 387 03(22) x 10-10 J
triton mass energy equivalent in MeV 2808.920 906(70) MeV
triton mass in u 3.015 500 7134(25) u
triton molar mass 3.015 500 7134(25) x 10-3 kg mol-1
triton-neutron magnetic moment ratio -1.557 185 53(37)
triton-proton magnetic moment ratio 1.066 639 908(10)
triton-proton mass ratio 2.993 717 0309(25)
unified atomic mass unit 1.660 538 782(83) x 10-27 kg

Source: http://physics.nist.gov/cuu/Constants/index.html - Latest 2013 CODATA values

note: Values are given in Concise Form: the number in parenthesis is the standard uncertainty, multiplied by the relative standard uncertainty.