In May 2019, certain fundamental constants that had been measured in SI units have had their numerical values fixed, with no uncertainty, thus defining the units. Of importance to electroanalytical chemistry are the values of the Boltzmann constant, the elementary charge, and the Avogadro constant. These are given in the table below, with calculated values of the Faraday constant (\(F = e·N_{\rm{A}}\)) and gas constant (\(R = k\cdot\!N_{\rm{A}}\)).

Table 1 Values of constants of importance to electrochemistry in the SI after 20 May 2019.

Constant	Symbol	Numerical value	Unit
elementary charge	_000245_	_027243_	_013926_
Boltzmann constant	_000095_	_027244_	_027245_
Avogadro constant	_022050_	_027246_	_027247_
Faraday constant	_010289_	_027248_	_027249_
molar gas constant	_009513_	_027250_	_021437_