This paper develops a model for determining an optimum parking layout of a given rectangular paved lot. The widths of access lanes used and the arrangement of the stalls created are subject to existing regulations. An attempt has been made to accommodate as many cars as possible. Several models are presented to incorporate driveways, the dimensions of the parking spaces, a non-rectangular lot, as well as an entrance to the parking lot. For example, Parking Lot B on the University of Waterloo campus has been redesigned to hold more cars.