Urban Air Mobility (UAM) vehicles have been proposed to mitigate urban traffic gridlock and reduce their associated air pollution . Currently, many of these electric vertical takeoff and landing (eVTOL) aircraft are being developed worldwide under various configurations. The purpose of this paper is to present a method for sizing that is independent of the vehicle configuration to provide a quick viability estimate of eVTOL concepts. Performance parameters such as range, speed, and payload capacity are computed along with general physical parameters like wing area and disk area to provide power requirement estimate and vehicle weight. The weight is used to indicate viability of the vehicle concept and its associated assumptions.