Service Oriented Architecture is a loosely coupled architecture designed to tackle the problem of Business Infrastructure alignment to meet the needs of an organization. A SOA based platform enables the enterprises to develop applications in the form of independent services. To provide scalable service interactions, there is a need to maintain services performance and have a good sizing guideline of the underlying software platform. Sizing aids in finding the optimum resources required to configure and implement a system that would satisfy the requirements of Business Process Integration being planned. A web based Sizing Tool prototype is developed using Java Application Programming Interfaces to automate the process of sizing the applications deployed on SOA platform that not only scales the performance of the system but also predicts its business growth in the future.