A technique for supporting the sizing of hierarchical computer resources is provided. The sizing support system includes a memory, a table definition module and field calculation module. The memory stores lower level resource data which indicates the kinds and the maximum number of lower level resources belonging to the resources of each hierarchy level, and resource data which indicates parameters of resources of each hierarchy level. The processing is executed in a unit of three levels. In the unit process of three levels, the table definition module generates a table frame indicating the possible configurations of first resource by referring the lower level resource data. The field calculation module calculates the performance and cost of the configuration in the table frame by referring the resource data.