Wind loads are generally divided into along-wind, across-wind, and torsional loads, but in reality they occur simultaneously in time and space. Furthermore, because they do not show their maximums at the same instant, they need to be combined appropriately. In this study, pressure measurements were conducted on atypical supertall buildings to investigate wind load combinations. Using a simplified reference model with four columns, analyses in the time domain were conducted, and this paper proposes combination rules based on the concept of combination factor that can be applied to atypical supertall buildings. The combination factor for a square model is approximately 0.5, and those for atypical models differ depending on building shape. Two methods are discussed in the determination of combination factors, and comparisons between peak normal stresses by analysis and combination factor show relatively good agreement, ranging mostly within +/- 5%. (C) 2015 American Society of Civil Engineers.