Among other things, one or more techniques and/or systems are provided for modeling a discrete device as a macro device. That is, the discrete device can comprise one or more parasitic elements, such as parasitic resistances and/or capacitances. Because values of the parasitic elements are unknown during pre-simulation of the discrete device, the discrete device can be modeled as a macro device, which can be used during pre-simulation to take into account the parasitic elements. For example, specified parameters, such as channel length, can be used to obtain a set of RC values that specify predicted values for the one or more parasitic elements of the discrete device. The discrete device can be modeled as the macro device using the set of RC values. In this way, the macro device can be used during pre-simulation to take into account the parasitic effects of parasitic elements of the discrete device.