Physical Constants

#

Constant

Symbol

Value

Units

1

Speed of light in vacuum

(c)

299792458 (exact)

m s^-1

2

Permeability of vacuum

(mu_0)

4 pi e-7 (exact)

N A^-2

3

Permittivity of vacuum

(epsilon_0)

8.854187817e-12

F m^-1

4

Newtonian constant of gravitation

(G)

6.67259e-11 ± 8.5e-15

m³ kg^-1 s^-2

5

Planck constant

(h)

6.6260755e-34 ± 4.0e-40

J s

6

Planck constant in eV

4.1356692e-15 ± 1.2e-21

eV s

7

h-bar

(h-bar)

1.05457266e-34 ± 6.3e-41

J s

8

h-bar in eV

6.582122e-16 ± 2.0e-22

eV s

9

Boltzmann constant

(k)

1.380658e-23 ± 1.2e-28

J K^-1

10

Boltzmann constant in eV

8.617385e-05 ± 7.3e-10

eV K^-1

11

Boltzmann constant in Hz

20836740000 ± 180000

K^-1 s^-1

12

Boltzmann constant in wavenumbers

69.50387 ± 0.00059

m^-1 K^-1

13

Electron mass

(m_e)

9.1093897e-31 ± 5.4e-37

kg

14

Electron mass in u

0.000548579903 ± 1.3e-11

u

15

Electron mass in eV

510999.06 ± 0.15

eV

16

Atomic mass unit

(u)

1.6605402e-27 ± 1.0e-33

kg

17

Standard atmosphere

(atm)

101325

Pa

18

Standard acceleration of gravity

(g_n)

9.80665

m s^-2

19

Electron volt

(eV)

1.60217733e-19 ± 4.9e-26

J

20

Planck mass

(m_p)

2.17671e-08 ± 1.4e-12

kg

21

Planck length

(l_p)

1.61605e-35 ± 1.0e-39

m

22

Planck time

(t_p)

5.39056e-44 ± 3.4e-48

s

23

Elementary charge

(e)

1.60217733e-19 ± 4.9e-26

C

24

Magnetic flux quantum

(Phi_0)

2.06783461e-15 ± 6.1e-22

Wb

25

Josephson frequency-voltage quotient

483597670000000 ± 1.4e+08

V^-1 s^-1

26

Quantized Hall conductance

3.87404614e-05 ± 1.7e-12

Omega^-1

27

Quantized Hall resistance

(R_H)

25812.8056 ± 0.0012

Omega

28

Bohr magneton

(mu_B)

9.2740154e-24 ± 3.1e-30

J T^-1

29

Bohr magneton in eV

5.78838263e-05 ± 5.2e-12

eV T^-1

30

Bohr magneton in Hz

13996241800 ± 4200

T^-1 s^-1

31

Bohr magneton in wavenumbers

46.686437 ± 1.4e-05

m^-1 T^-1

32

Bohr magneton in kelvins

0.6717099 ± 5.7e-06

K T^-1

33

Nuclear magneton

(mu_N)

5.0507866e-27 ± 1.7e-33

J T^-1

34

Nuclear magneton in eV

3.15245166e-08 ± 2.8e-15

eV T^-1

35

Nuclear magneton in Hz

7622591.4 ± 2.3

T^-1 s^-1

36

Nuclear magneton in wavenumbers

0.0254262281 ± 7.7e-09

m^-1 T^-1

37

Nuclear magneton in kelvins

0.0003658246 ± 3.1e-09

K T^-1

38

Fine structure constant

(alpha)

0.00729735308 ± 3.3e-10

39

Inverse fine structure constant

137.0359895 ± 6.1e-06

40

Rydberg constant

(Ry)

10973731.534 ± 0.013

m^-1

41

Rydberg constant in Hz

3.2898419499e+15 ± 3.9e+06

s^-1

42

Rydberg constant in joules

2.1798741e-18 ± 1.3e-24

J

43

Rydberg constant in eV

13.6056981 ± 4.0e-06

eV

44

Bohr radius

(a_0)

5.29177249e-11 ± 2.4e-18

m

45

Hartree energy

(E_h)

4.3597482e-18 ± 2.6e-24

J

46

Hartree energy in eV

27.2113961 ± 8.1e-06

eV

47

Quantum of circulation

0.000363694807 ± 3.3e-11

m² s^-1

48

Electron-muon mass ratio

0.00483633218 ± 7.1e-10

49

Electron-proton mass ratio

0.000544617013 ± 1.1e-11

50

Electron-deuteron mass ratio

0.000272443707 ± 6e-12

51

Electron-alpha-particle mass ratio

0.000137093354 ± 3e-12

52

Electron specific charge

-175881962000 ± -53000

C kg^-1

53

Electron molar mass

5.48579903e-07 ± 1.3e-14

kg mol^-1

54

Electron Compton wavelength

(lambda_C)

2.42631058e-12 ± 2.2e-19

m

55

Electron Compton wavelength over 2 pi

(lambda-bar_C)

3.86159323e-13 ± 3.5e-20

m

56

Electron classical radius

(r_e)

2.81794092e-15 ± 3.8e-22

m

57

Electron Thomson cross section

(sigma_e)

6.6524616e-29 ± 1.8e-35

m²

58

Electron magnetic moment

9.2847701e-24 ± 3.1e-30

J T^-1

59

Electron magnetic moment in Bohr magnetons

1.001159652193 ± 1.0e-11

60

Electron magnetic moment in nuclear magnetons

1838.282 ± 3.7e-05

61

Electron magnetic moment anomaly

(a_e)

0.001159652193 ± 1.0e-11

62

Electron g-factor

(g_e)

2.002319304386 ± 2.0e-11

63

Electron-muon magnetic moment ratio

206.766967 ± 3.0e-05

64

Electron-proton magnetic moment ratio

658.2106881 ± 6.6e-06

65

Muon mass

1.8835327e-28 ± 1.1e-34

kg

66

Muon mass in u

0.113428913 ± 1.7e-08

u

67

Muon mass in eV

105658389 ± 34

eV

68

Muon-electron mass ratio

206.768262 ± 3.0e-05

69

Muon molar mass

0.000113428913 ± 1.7e-11

kg mol^-1

70

Muon magnetic moment

4.4904514e-26 ± 1.5e-32

J T^-1

71

Muon magnetic moment in Bohr magnetons

0.00484197097 ± 7.1e-10

72

Muon magnetic moment in nuclear magnetons

8.8905981 ± 1.3e-06

73

Muon magnetic moment anomaly

(a_mu)

0.001165923 ± 8.4e-09

74

Muon g-factor

(g_mu)

2.002331846 ± 1.7e-08

75

Muon-proton magnetic moment ratio

3.18334547 ± 4.7e-07

76

Proton mass

(m_p)

1.6726231e-27 ± 1.0e-33

kg

77

Proton mass in u

1.00727647 ± 1.2e-08

u

78

Proton mass in eV

938272310 ± 280

eV

79

Proton-electron mass ratio

1836.152701 ± 3.7e-05

80

Proton-muon mass ratio

8.8802444 ± 1.3e-06

81

Proton specific charge

95788309 ± 29

C kg^-1

82

Proton molar mass

0.00100727647 ± 1.2e-11

kg mol^-1

83

Proton Compton wavelength

(lambda_C,p)

1.32141002e-15 ± 1.2e-22

m

84

Proton magnetic moment

1.41060761e-26 ± 4.7e-33

J T^-1

85

Proton magnetic moment in Bohr magnetons

0.001521032202 ± 1.5e-11

86

Proton magnetic moment in nuclear magnetons

2.792847386 ± 6.3e-08

87

Diamagnetic shielding correction for protons (H_2 O, spherical sample, 298.15 K)

(sigma_H2O)

2.5689e-05 ± 1.5e-08

88

Shielded proton moment (H_2 O, spherical sample, 298.15 K)

(mu_p')

1.41057138e-26 ± 4.7e-33

J T^-1

89

Shielded proton moment in Bohr magnetons

0.001520993129 ± 1.7e-11

90

Shielded proton moment in nuclear magnetons

2.792775642 ± 6.4e-08

91

Proton gyromagnetic ratio

(gamma_p)

267522128 ± 81

T^-1 s^-1

92

(gamma_p)

42577469 ± 13

T^-1 s^-1

93

Proton gyromagnetic ratio, uncorrected (H_2 O, spherical sample, 298.15 K)

(gamma_p')

267515255 ± 81

T^-1 s^-1

94

(gamma_p'/2pi)

42576375 ± 13

T^-1 s^-1

95

Neutron mass

(m_n)

1.6749286e-27 ± 1.0e-33

kg

96

Neutron mass in u

1.008664904 ± 1.4e-08

u

97

Neutron mass in eV

939565630 ± 280

eV

98

Neutron-electron mass ratio

1838.683662 ± 4.0e-05

99

Neutron-proton mass ratio

1.001378404 ± 9e-09

100

Neutron molar mass

0.001008664904 ± 1.4e-11

kg mol^-1

101

Neutron Compton wavelength

(lambda_C,n)

1.3195911e-15 ± 1.2e-22

m

102

Neutron magnetic moment

9.6623707e-27 ± 4.0e-33

J T^-1

103

Neutron magnetic moment in Bohr magnetons

0.00104187563 ± 2.5e-10

104

Neutron magnetic moment in nuclear magnetons

1.91304275 ± 4.5e-07

105

Neutron-electron magnetic moment ratio

0.00104066882 ± 2.5e-10

106

Neutron-proton magnetic moment ratio

0.68497934 ± 1.6e-07

107

Deuteron mass

(m_d)

3.343586e-27 ± 2.0e-33

kg

108

Deuteron mass in u

2.013553214 ± 2.4e-08

u

109

Deuteron mass in eV

1875613390 ± 570

eV

110

Deuteron-electron mass ratio

3670.483014 ± 7.5e-05

111

Deuteron-proton mass ratio

1.999007496 ± 6e-09

112

Deuteron molar mass

0.002013553214 ± 2.4e-11

kg mol^-1

113

Deuteron magnetic moment

(mu_d)

4.3307375e-27 ± 1.5e-33

J T^-1

114

Deuteron magnetic moment in Bohr magnetons

0.0004669754479 ± 9.1e-12

115

Deuteron magnetic moment in nuclear magnetons

0.85743823 ± 2.4e-08

116

Deuteron-electron magnetic moment ratio

0.000466434546 ± 9.1e-12

117

Deuteron-proton magnetic moment ratio

0.3070122035 ± 5.1e-09

118

Avagadro constant

(N_A)

6.0221367e+23 ± 3.6e+17

mol^-1

119

Atomic mass constant

(m_u)

1.6605402e-27 ± 1.0e-33

kg

120

Atomic mass constant in eV

931494320 ± 280

eV

121

Faraday constant

(F)

96485.309 ± 0.029

C mol^-1

122

Molar Planck constant

3.99031323e-10 ± 3.6e-17

J s mol^-1

123

(N_A hc)

0.11962658 ± 1.1e-07

J m mol^-1

124

Molar gas constant

(R)

8.31451 ± 7.0e-05

J mol^-1 K^-1

125

Molar volume (ideal gas), STP

(V_m)

0.0224141 ± 1.9e-07

m³ mol^-1

126

Loschmidt constant

(n_0)

2.686763e+25 ± 2.3e+20

m^-3

127

Stefan-Boltzmann constant

(sigma)

5.67051e-08 ± 1.9e-12

W m^-2 K^-4

128

First radiation constant

(c_1)

3.7417749e-16 ± 2.2e-22

W m²

129

Second radiation constant

(c_2)

0.01438769 ± 1.2e-07

m K

130

Wien displacement law constant

(b)

0.002897756 ± 2.4e-08

m K