The present invention relates to a method and system for providing advertising inventory information. More specifically, the present invention relates to a method and system for providing advertising inventory information in response to demographic inquiries. In an exemplary embodiment, a server responds to a demographic query. Based on the query, the server queries an advertising inventory database and a contract database to retrieve relevant information. Using the relevant information, the total inventory and the total sold inventory are obtained. Using the now obtained total inventory and the total sold inventory information, the server then provides an estimation of the total available inventory matching the query.