The critical micelle concentration and the effective degree of dissociation of micelles (α) of sodium dodecyl sulfate, which is the most extensively used surfactant in emulsion polymerization systems, were determined in the presence of various amounts of sodium carbonate and potassium persulfate, and some monomers, such as methyl methacrylate, butyl acrylate, and styrene by means of the conductometric procedure at 25 °C. In addition, the other micellization parameters, such as aggregation number and number of counter-ions per micelle, were computed directly from the obtained conductivity measurements data. The effect of the combination of sodium carbonate and potassium persulfate, on the critical micelle concentration of the sodium dodecyl sulfate solutions was studied at 60 °C (emulsion reaction temperature). The empirical formulations derived provide an easy way to estimate the critical micelle concentration and the effective degree of dissociation of micelles of a system at a given electrolyte and monomer concentration.