The estimation of the software cost remains one of the most challenging problems in software engineering; as a preliminary estimate of cost includes many elements of uncertainty. Reliable and early estimates are difficult to obtain because of the lack of the detailed information about the future system at an early stage. However, the early estimates are really important when bidding for a contract or determining whether a project is feasible in terms of cost-benefit analysis. Estimators often rely on their past experiences for the prediction of effort for software projects. In this Book, we discussed a software cost estimation tool that helps commercial software-development organizations to effectively and quantitatively measure and analyze the software metrics based upon the functional requirements, operational constraints and organization s capability to handle a project. The new cost estimation method is proposed for the iterative software development projects.