Basis of Estimate a tool used in the field of project management by which members of the project team, usually estimators, project managers, or cost analysts, calculate the total cost of the project. Through carefully planned equations, hierarchical listing of elements, standard calculations, checklists of project elements and other methods, the project team adds in all expenses of a project, from labor to materials to administrative costs. These calculations formulate a Basis of Estimate which is, when completed, a number that can be used to determine the ability of the firm or company to carry out the project, or used as a tool in competing for a contract bid or otherwise proposing the project to another.