Conventionally, electric fields in a development nip are often calculated for well-defined patterns (solid areas and isolated lines) or for a given charge distribution on the photoconductor surface. We propose an alternative method for field calculation based on various physical parameters of the development system. It uses a set of laser and photoconductor parameters to compute the exposure energy on the photoconductor surface, and the corresponding photoconductor surface potential is obtained from the Photo-Induced Discharge Characteristics (PIDC) of the photoconductor. The surface potential is then used as a boundary condition for solving Poisson's equation. The normal and horizontal fields are subsequently obtained by taking the negative gradient of the voltage. This method accounts for what is commonly known as dot-overlapping. Thus, electric fields anywhere in the gap for an arbitrary input bitmap can be calculated. Using our field model, simulation results from various input patterns are presented.