The molar conductivity of an electrolyte solution is defined as its conductivity divided by its molar concentration.
where:
: κ is the measured conductivity (formerly known as specific conductance),
: c is the molar concentration of the electrolyte.
The SI unit of molar conductivity is siemens metres squared per mole (S m mol). However, values are often quoted in S cm mol. In these last units, the value of Λ may be understood as the conductance of a volume of solution between parallel plate electrodes one centimeter apart and of sufficient area so that the solution contains exactly one mole of electrolyte.