Ionic piezoresistance, the effect of lattice strain on ionic conductivity, is an important concept that needs to be harnessed to engineer the next generation of fast ionic conductors. To date there have been many reports of strain affecting changes in the level of ionic conductivity in solid electrolytes. The fundamental understanding is, however, still lacking, with limited experimental quantification of the magnitude of the effect. Here, we propose using the ionic piezoresistive coefficient, the constant of proportionality between the strain state and the change in conductivity, as a quantitative measure of this effect and detail a novel technique we have developed to quantify this in high temperature ionically conducting materials.