Fundamental Physical Constantsaa
| Quantity | Symbol | Value(s) |
| Atomic mass unit or Dalton | amu, u, Da | 1.660538782 × 10−27 kg 931.494028 × 106 eV/c2 |
| Avogadro number | L, NA | 6.02214179 × 1023 mol−1 |
| Boltzmann constant | k | 1.3806504 × 10−23 J K−1 |
| Elementary charge | e | 1.602176487 × 10−19 C |
| Gravitational constant | G | 6.67428 × 10−11 m3 kg−1 s−2 |
| Mass of electron | me | 9.10938215 × 10−31 kg 8.18710438 × 10−14 J/c2 0.510998910 MeV/c2 5.4857990943 × 10−4 u |
| Mass of proton | mp | 1.672621637 × 10−27 kg 1.503277359 × 10−10 J/c2 938.272013 MeV 1.00727646677 u |
| Molar gas constant | R | 8.314472 J K−1 mol−1 0.08205746 L atm K−1 mol−1 K for kelvin |
| Permeability of vacuum Magnetic constant | μ0 | 4π × 10−7 N A−2 N for newton and A for ampere. |
| Permittivity of vacuum Electric constant | ε0 | 8.854187817 × 10−12 F m−1 |
| Planck constant | h | 6.62606896 × 10−34 J s 4.13566733 × 10−15 ev s 6.62606896 × 10−27 erg s |
| Speed of light in vacuum | c | 2.99792458 × 108 m/s |
| Stefan-Boltzmann constant | σ | 5.670400 × 10−8 W m−2 K−4 W for watt |
a Courtesy of the National Institute of Standards and Constants (NIST).
