The electricity master plan is very important to anticipate the increase in annual electricity needs so that it remains flexible and can withstand load growth. Based on the 2021-2030 RUPTL, the projected peak load demand for electrical energy in DKI Jakarta Province is projected to increase by an average of 3.5% annually. Referring to SPLN 50:1997, transformer loading should not exceed 80%. This study developed a MATLAB Graphic User Interface (GUI)-based simulation program to determine the criteria, capacity, and number of transformers and distribution substations required in an area. Planning for the addition of distribution equipment such as transformers and distribution substations aims to minimize transformer loading that exceeds operating standards and reduce losses due to load growth. The results of the study in Senayan Village showed that transformer loading had exceeded 80% in the 8th year, thus requiring an additional transformer capacity of 375 kVA. By simulating the addition of a 250 kVA transformer unit, it is known that Senayan Village requires 9 additional transformer units and 7 distribution substation units when it reaches the 10th year. To increase effectiveness, the MATLAB GUI is integrated with a Geographic Information System (GIS). This integration provides a comprehensive visualization of transformer and distribution substation locations, including name and capacity information. This planning method can be applied to other sub-districts by adjusting for their respective load growth, simplifying the electricity planning process.