Fundamental Physical

Constant

Numerical Value.

Relative Standard Uncertainty, 2010

Numerical Value.

Relative Standard Uncertainty, 2014

Numerical Value.

Relative Standard Uncertainty, 2018

Characteristic Impedance of Vacuum $Z_0$ , Ω

376.730313461

exact

376.730313461

exact

376.730313668

1.5 × 10⁻¹⁰

Newtonian Constant of Gravitation G,

×10⁻¹¹ m³∙kg⁻¹∙s⁻²

6.67384

1.2 × 10⁻⁴

6.67408

4.7 × 10⁻⁵

6.67430

2.2 × 10⁻⁵

Planck constant h, ×10⁻³⁴ J∙Hz⁻¹

6.62606957

4.4 × 10⁻⁸

6.626070040

1.2 × 10⁻⁸

6.62607015

exact

Speed of Light in Vacuum c, m∙s⁻¹

299792458

exact

299792458

exact

299792458

exact

Vacuum Electric Permittivity ${\epsilon }_0$ , ×10⁻¹² F∙m⁻¹

8.8541878176

exact

8.8541878176

exact

8.8541878128

1.5 × 10⁻¹⁰

Vacuum Magnetic Permeability ${\mu }_0$ , ×10⁻⁶ N∙A⁻²

1.25663706144

exact

1.25663706144

exact

1.25663706212

1.5 × 10⁻¹⁰

Elementary charge C, ×10⁻¹⁹

1.602176565

2.2 × 10⁻⁸

1.6021766208

6.1 × 10⁻⁹

1.602176634

exact

Electron Charge to Mass Quotient $-e/m_e$ ,

×10¹¹ C∙kg⁻¹

−1.758820088

2.2 × 10⁻⁸

−1.758820024

6.2 × 10⁻⁹

−1.75882001076

3.0 × 10⁻¹⁰

Fermi Coupling Constant $G_F/{\left(ћc\right)}^3$ ,

×10⁻⁵ Ge∙V⁻²

1.166364

4.3 × 10⁻⁶

1.1663787

5.1 × 10⁻⁷

1.1663787

5.1 × 10⁻⁷

Fine-Structure Constant α, ×10⁻³

7.2973525698

3.2 × 10⁻¹⁰

7.2973525664

2.3 × 10⁻¹⁰

7.2973525693

1.5 × 10⁻¹⁰

Hartree Energy $E_h$ , ×10⁻¹⁸ J

4.35974434

4.4 × 10⁻⁸

4.359744650

1.2 × 10⁻⁸

4.3597447222071

1.9 × 10⁻¹²

Rydberg Constant $R_{\infty }$ , m⁻¹

10973731.568539

5.0 × 10⁻¹²

10973731.568508

5.9 × 10⁻¹²

10973731.568160

1.9 × 10⁻¹²