Websites hide thousands of links and sub-links. Websites’ links contain a huge amount of information and knowledge. This research concentrates mainly on the difficulty of early prediction of web structure size at the beginning of Website Development Life Cycle (WDLC), especially during planning and gathering requirements. There is a lack of finding an appropriate mechanism to assist developers in these steps. The objective of this research is to measure the logical size of a website in order to predict the development time and cost earlier before the development process based on based on the website contents and its internal structure. This objective includes three sub-objectives. First, analysis of seven classes of websites to collect real data sets. Second, extracting a set of relations from the gathered data and use these relations to establish a proposed model. Third, apply the gathered data in the proposed model to predict the development time and cost of a website. This research provides strong and important results that would help developers before the development process to predict total development time and cost which in turn used directly to specify development tools, draw project plan, formulate contract conditions and determine project duration and final price.