Studies indicate that there is a relationship between project cost and construction time for different construction markets. The purpose of this study was to validate the time-cost relationship model developed by Bromilow et al. (1980) in the context of commercial, residential, and industrial construction projects in India. The model was extended to include the magnitude of the projects in terms of gross floor area and construction types, to determine whether these variables also have an effect on project duration. Data related to 99 construction projects from all over India were obtained. The SPSS® program and the General Linear Model were used for analysis. The results show a statistically significant relationship between construction time and magnitude of the project, measured by gross floor area, at the level of significance (p-value) of < 0.0001. This variable, when introduced the model, presumably acts as a proxy for actual construction cost. Construction type did not have a statistically significant relationship with construction time. A prediction model of construction time has been developed based on the results of the study. This model will be useful to constructors who work at an international level.