Potentials of Common Reference Electrodes

Potentials of Common Reference Electrodes - Dr. Bob's BuzzThe following tables give the potentials of several commonly used reference electrodes. Various filling solutions are listed where data was available. Note that the nature and concentration of the filling solution can dramatically change the potential! When you look through the scientific literature, be sure the author has specified the filling solution!

If you are confused about converting from one reference electrode to another, read our explanation.

Calomel Hg/Hg2Cl2
Silver-silver chloride Ag/AgCl
Mercury-mercury oxide Hg/HgO
Mercury-mercurous sulfate Hg/Hg2SO4
Silver-silver sulfate Ag/Ag2SO4
Copper-copper sulfate Cu/CuSO4



  • In some cases, two slightly different potentials are listed for the same electrode/filling solution. Some of the values are ‘standard potentials’ or potentials of cells without liquid junction. Other values (‘LJ’ in tables, below) are for cells which include a liquid junction potential.
  • Values in italics have been calculated from the suitable (LJ or non-LJ) potentials in these tables. Other values have been taken directly from the reference cited.
Potentials of Common Reference Electrodes