Existing applications are getting modernized to cloud. Due to the complex nature of the modernized application, enterprise are having apprehension towards the successful adoption of newer technology specifically cloud computing. Return on investment on this technology needs to be validated before the start of the modernization journey. How much of investment is required, how the modernization characteristics will impact the overall cost needs a strategic view from cost perspective. Calculation of ROI requires a unique framework by considering all the challenges and the enhancements which is going to be made for the enterprise modernization application. To validate the feasibility from ROI perspective, calculating ROI should be more realistic and predictive enough to justify the effort and more importantly reduce the risk for enterprise on this very important journey. In this paper we analyse the important cloud attributes which impacts the ROI parameters by considering the modernization characteristics. We come up with detailed taxonomy which impacts the ROI calculation along with high level framework for ROI on all aspects. Scenario based evaluation are conducted to showcase that the approach proposed in this paper will be useful for enterprise in understanding the dynamic nature of the modernized application before start of the modernization. © Research India Publications.