Despite some theoretical and technical criticism, scholars largely acknowledge the influence of universities' ranking positions on the preferences of fund providers, academics and students, nationally and internationally. Considering their noticeable contribution to university rankings, prominent indicators can guide university leaders to develop better strategies by targeting common aspects of international ranking systems. The purpose of this research is therefore to specify the significant indicators and to examine their individual weight through an expanded indicator-set of international university rankings. The research benefited from the predictive approach of correlational research. The dataset was composed of universities' scores in the 2018 ARWU, THE, QS and URAP world university rankings and includes the scores of 224 universities. The data were re-organised following the expanded indicator-set previously formulated by the researcher. Regression analyses were then employed in two steps to explore significant predictors through the expanded indicator-set. The researcher also re-calculated the percentage values of seven combined indicators: citation, income, internationalisation, prize, publication, reputation and ratios/degrees. The findings showed that while all these indicators are statistically significant, the components of research reputation contribute 73.71% to universities' ranking scores. On the other hand, income is the only negative contributor with a weight of - 1.78%. The research also revealed that when comparing two scores based on re-calculated and assigned weights, only 19 universities occupy the same position among the 224 universities. Following these results, the researcher then discusses various policies and practices with the potential to expedite universities' ranking success. Considering the data reliability and longitudinal feasibility, several recommendations were also developed for further research on university ranking systems.