An empirical characterization of the void fraction in the spray region of liquid jets emanating from a twin-fluid atomizer has been carried out. The present study evolves under primary breakup criteria. That is, the respective breakup length extracted from flow visualization techniques are successfully utilized to find a better functional correlation for the area void fraction with longitudinal distance. The resultant function enables extracting the axial location at which complete atomization occurs for the range of conditions tested. To make the analysis more appealing in the practical domain, the concept of effective jet diameter and associated stretching factor at the nozzle exit plane were introduced. Hence, the validity of results will not be limited to the present test conditions.