The presence and location of the critical micelle concentration is easily identified by sharp changes to the stoichiometric ratios in a dataset derived from 35 literature sources. In the case of the acid:extractant ratios in the absence of aqueous metal ions, stoichiometries between 0.5 and 1 HNO 3 per extractant are observed before the CMC, with a 2-4x increase observed after a critical acid concentration is reached. The magnitude of the increase follows previously studied trends in the magnitude of the dipole moments of the extractants, which impact the strength of the hydrogen bonding interactions with the extracted acid and water. The specific acid concentration of the statistically derived CMC values agrees with most literature values, but clearly identifies outliers in the reported data. Additionally, we observe that higher extractant concentrations require higher aqueous [HNO 3 ] to achieve the CMC transition, and many literature studies do not go to high enough acid concentrations for this to occur. In considering metal-extracting systems, specifically the extraction of Am 3+ and Eu 3+ , the data analysis indicates little to no change in the location of the CMC relative to the metal-free extraction systems. Before the CMC, there are large changes to the metal:extractant ratios, indicating the growth of the preferred reverse micelle sizes before the CMC. Thus the stoichiometric ratios systematically decrease at a significant rate with increasing acid concentration prior to the CMC. After the CMC, the metal:extractant ratio stabilizes with very little change upon increasing acid concentration. This indicates that after the CMC, a stable size distribution is reached for the reverse micelle aggregates that is insensitive to the aqueous acid concentration.