Due to the depletion of fossil fuels renewable energy sources are gaining the utmost importance. As solar energy is available in abundance so it is one of the main source of energy .This spark is also due to reduction in the cost of the Photovoltaic cell (PV) which is the result of technological advancement in the field of power electronic. There are numerous application for the solar energy .One of the application is in the field of water pumping system which earlier incorporated diesel prime mover. But the advancement in technology resulted in the advancement in of solar based water pumping system. To improve the efficiency of the water pumping system and to estimate the cost and performance the pre-sizing of the system is done .In this paper software PV systused for the pre-sizing of solar based water pumping is studied . The detailed simulation steps are used in this software tool are discussed in this paper. The paper deals with the process involved in presizing of solar based water pumping system using PV syst while considering Maximum power point tracking converter and brushless DC Motor.