Trends in modern architectural design have led to the proliferation of large atrium buildings. Fires in such buildings can result in significant loss of life and property damage as the propagation of smoke is unimpeded. The design of effective smoke management systems for atrium buildings requires reliable calculation methods to predict the quantity of smoke produced. Numerical modeling using FDS is performed in this research to examine the entrainment processes as the smoke flows from a compartment, through a balcony before discharging into an atrium. Different fire sizes and geometrical configurations are analyzed and empirical correlations are proposed for the mass flow rate of smoke at the spill edge and for the entrainment as the smoke rotates upwards around the spill edge. These correlations show good agreement with experimental data from previous work.