Surfactants find a wide variety of commercial application in enhancing the solubility of poorly soluble solutes, especially sensitive biological compounds. In solution surfactant molecules aggregate into micelles of characteristic size and shape depending on its molecular structure and size. The concentration at which micelles start to form is called critical micelle concentration (cmc). The cmc of a surfactant in a given solvent is of great importance in understanding and predicting micelle behaviour which plays an important role for choosing suitable chemicals for specific industrial applications techniques are available in the literature to predict cmc. The early models were based on semiempirical equations. Recently, thermodynamic model and molecular thermodynamic models are used by researchers to predict cmc. This paper critically evaluates the techniques available for estimating cmc.