In the synthesis of heat exchanger networks, the estimation of minimum area requirements plays an important role since it allows for the prediction of investment requirements ahead of design. In this work, a method to calculate the area target and capital cost target for the synthesis of heat exchanger networks is presented. The method is suitable for cases in which there are significant differences in the film heat transfer coefficients among process streams and when different cost laws for heat exchangers are considered. The area targeting algorithm is based on the concept of AT-contribution for each stream. Two examples are shown to illustrate the application of the proposed method.