Physical Constants Reference Table | CODATA Values & Units

c Speed of Light in Vacuum Value: 299,792,458 m/s

G Gravitational Constant Value: 6.67430 × 10⁻¹¹ m³/(kg·s²)

h Planck Constant Value: 6.62607 × 10⁻³⁴ J·s

ℏ Reduced Planck Constant Value: 1.05457 × 10⁻³⁴ J·s

k_B Boltzmann Constant Value: 1.38065 × 10⁻²³ J/K

N_A Avogadro Number Value: 6.02214 × 10²³ mol⁻¹

R Gas Constant Value: 8.31446 J/(mol·K)

σ Stefan-Boltzmann Constant Value: 5.67037 × 10⁻⁸ W/(m²·K⁴)

e Elementary Charge Value: 1.60218 × 10⁻¹⁹ C

ε₀ Vacuum Permittivity Value: 8.85419 × 10⁻¹² F/m

μ₀ Vacuum Permeability Value: 1.25664 × 10⁻⁶ N/A²

k_e Coulomb Constant Value: 8.98755 × 10⁹ N·m²/C²

Φ₀ Magnetic Flux Quantum Value: 2.06783 × 10⁻¹⁵ Wb

m_e Electron Mass Value: 9.10938 × 10⁻³¹ kg

m_p Proton Mass Value: 1.67262 × 10⁻²⁷ kg

m_n Neutron Mass Value: 1.67493 × 10⁻²⁷ kg

u Atomic Mass Unit Value: 1.66054 × 10⁻²⁷ kg

a₀ Bohr Radius Value: 5.29177 × 10⁻¹¹ m

R_∞ Rydberg Constant Value: 1.09737 × 10⁷ m⁻¹

α Fine-Structure Constant Value: 7.29735 × 10⁻³ ≈ 1/137 dimensionless

g Standard Gravity Value: 9.80665 m/s²

atm Standard Atmosphere Value: 101,325 Pa

F Faraday Constant Value: 96,485.3 C/mol

b Wien Displacement Constant Value: 2.89777 × 10⁻³ m·K

eV Electron Volt Value: 1.60218 × 10⁻¹⁹ J