An estimation system for estimating an injection-molding related cost comprises an input unit, storage, a data processing unit, and an output unit. The storage stores a mold estimation function for each of cost items of a mold used to produce a molded product, and a mold estimation reference value table for recording mold estimation reference values in association with prescribed conditions. The data processing unit acquires a fabrication condition of the molded product through the input unit, reads the mold estimation function and one of the mold estimation reference values from the storage corresponding to the fabrication condition, and estimates a cost of the mold based on the mold estimation function and the selected mold estimation reference value. The output unit outputs a mold cost estimation result made by the data processing unit.