Embodiments of the present invention provide systems, methods, and computer program products for modeling and estimating costs for a project, such as a construction or remodeling project. For example, embodiments of the present invention provide a project cost modeling system having a communication interface configured to receive a first level input for a first level project parameter from a user, a memory configured to store a rule, and a processor operatively connected to the communication interface and the memory and configured to determine a second level project parameter and a second level input for the second level project parameter based at least partially on a comparison of the first level input to the rule. The system is further configured to compute cost estimates and provide cost models based at least partially on the first level input, the second level input, and/or information about other projects stored in the memory.