Building Information Modeling (BIM) can store information of building elements and provide a computational platform for physical analyses for building systems. BIM can resolve several problems throughout various phases of design (as well as construction and operation). While use-cases such as daylight or energy analysis widely take advantage of this computational power, there is no integrated acoustical analysis tool or any external programs with acceptable interoperability within the BIM ecosystem. This study investigates the possibility of developing a BIM-based calculation method based on the most widely used design authoring tool in North America, i.e., Autodesk Revit, to estimate the acoustical properties of buildings with acceptable accuracy and details. A novel algorithm is designed to calculate reverberation time (RT), one of the most critical acoustic indicators of building spaces. The algorithm extracts geometric information from the BIM (i.e., the model); matches it with the physical properties provided by an open-source library; performs the analysis; visualizes the results on the model. The tool is tested over several case studies, and the results have been verified and validated using other existing methods. In the paper, we have studied the acoustical properties of an educational building using the designed tool under various scenarios.