IEC 61970 and 61968, which are commonly referred as Common Information Model (CIM), are proposed to facilitate integration of EMS applications and information exchange between EMS systems with propitiatory data structures. To use communication network in an optimized manner, it is necessary to partition the potentially voluminous data into subsets given their sources, expected exchange frequency, and subscribing applications. In response to these requirements, the concept of CIM profiles is brought up by CIMug. In this paper, functions illustrating the dependency between exchange data volume and basic grid parameters for each data profile are presented. A CIM/XML/RDF file for a generally available 40 bus test system (CIM 13) and examples provided by standards are used as references. The method is validated by estimating the data sizes of similarly available 100bus and 60bus test systems that are modeled according to CIM 13 as well. The contribution of this paper is that it provides ICT system designers with a means to estimate the corresponding requirements for various CIM/XML based data exchange patterns. The estimations are performed based on commonly known grid parameters such as number of buses, branches, generators, transformers and loads together with execution frequency of particular grid planning and operation applications.