Fundamental Physical Constants --- CODATA 2016 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 2016 CODATA values
note: Values are given in Concise Form: the number in parenthesis is the standard uncertainty, multiplied by the relative standard uncertainty.