This paper presents models that estimate the active clay content of the soil based on the correlation between the ratio of the second and first norm of the idealized fall cone curve (distance factor) and the arithmetic difference between the plasticity index and the clay content (clay index). The models were developed based on an analysis of 306 test results of clay content and Atterberg limits collected from the literature. The models were found to compute the active clay limit reasonably well, with most of the calculated results falling within the statistical testing bound of ±12 as provided in AASHTO T88-10.