Hospital operating theaters often face the problem of unscheduled emergency arrivals that should be treated as soon as possible. In practice different policies are used to allocate these emergency patients to the operating rooms. These policies are (1) keeping operating rooms empty and available for emergency arrivals; (2) treating emergency patients in elective operating rooms, postponing elective patients; and (3) a mix of these two policies. The use of a specific policy affects performance (e.g., utilization, waiting times, overtime). Currently, these effects are not clear, and there is no agreement on what works ‘best’ for a specific hospital. Using discrete-event simulation, we evaluate the policies for many case characteristics such as hospital size, patient case mix, and fraction of (emergency) patients. We gathered the simulation results in a tool called OR analyzer. This tool is made available online and allows healthcare practitioners to gain insight into the effects of the scheduling policies in settings similar to their specific hospital setting. In addition, this tool allows others researching emergency scheduling policies to frame their hospital settings and compare results.