The apparatus and method for estimating the size of content being received before the actual transmission of the data utilizes Electronic Service Guide (ESG) information. The ESG information assists a client device in obtaining file information before the file is actually transmitted by the source of the same. In this manner, the power supply of the user device can be managed more efficiently and provide the user with the ability to make storage determinations at their user device before expending the power resources necessary to obtain (i.e., download) and store a particular file of interest to the user without requiring any user intervention.