This construction management system is provided with: a construction amount data calculation unit which calculates construction amount data for a construction site on the basis of the current topography and the planned topography of the construction site; a work rate data acquisition unit which acquires work rate data indicating specific conditions of work machinery for construction on the construction site; a construction plan data calculation unit which, on the basis of the construction amount data and the work rate data, calculates a construction plan corresponding to a target construction period and calculates the construction cost if construction is carried out according to said construction plan; and a construction plan data output unit which outputs the construction cost corresponding to the target construction period to an output device.
