There are a variety of techniques developed in order to improve the efficiency of electrical systems and reduce cost of providing electricity to the consumer. This paper presents a new technique for power-factor capacity calculation in medium-sized industrial/commercial setups. Various loads of similar nominal power-factor are categorized and demand-factor of loads is so selected that it has engineering justifications. The developed system works on the principle of low-voltage power-factor correction, which substantially reduces electricity bill and increases loading-capacity of the electrical system. It allows commercial and industrial consumers to save on their power cost appreciably. This work utilizes software, which takes few inputs and produces numerous useful results. Adoption of this system can help the user in computing compensation-capacity, system KVA (size of transformer) and cost of compensation. A feature of this system is prediction of low PF penalty, Moreover, it also suggests the tentative payback period.