Evaluating the performance of construction projects has traditionally been undertaken by studying some classic performance metrics, such as cost and schedule, that are typically assessed separately. Even when these metrics are combined, it is done in the form of some opinion-based performance scoring that is inherently subjective. To address this issue, this paper presents the development, mathematical formulation, and validation of the Project Overall Performance (POP) model; a comprehensive data-based model that evaluates the performance of construction projects from the contractors' perspective. The POP model uses quantitative performance metrics spanning five key performance areas, namely cost, schedule, quality, communication among project teams, and change management, to assess the performance of construction projects. The novelty of the POP is that it uses performance data from 32 construction projects to derive the weights (relative importance) of the performance metrics and areas. Further, POP was correlated to projects' overhead and profit (O&P), such that contractors may use POP to understand why or how a project's O&P performs as expected or not as expected. The results of the POP scoring and analysis process showed that change management has the greatest impact on the POP score at 32% followed by schedule performance at 24%.