One of the most important duties of an engineer or an architect is to prepare the probable cost of the proposed building. This is also called as an estimate. The estimate is prepared by calculating the required quantities and calculating the costs at the suitable rates, in order to obtain the probable expenditure incurred during execution of the work or structure. This chapter explores the types of estimates. For preliminary studies of various aspects of a work or project, a preliminary estimate is required to determine the financial position and the administrative sanction policy of the competent administrative authority. Cube rate estimate is a preliminary estimate or an approximate estimate. It is prepared on the basis of the cubic content of the construction. The specifications deal with the methods of execution, qualities of material, nature of labor to be employed, proportions in which materials are to be mixed, measurement of work, and so on.