Power loss in electricity distribution systems is a major challenge that can reduce energy delivery efficiency. This study focuses on reducing these losses in medium voltage distribution networks, especially in the Sindanglaut Feeder in the Ciledug customer service unit of the State Electricity Company. The analysis used load flow simulation using ETAP 12.6.0 software, with an optimization strategy to increase the cable cross-section from 150 mm² to 240 mm² to assess its impact on voltage reduction and distribution efficiency. The simulation results showed that, before optimization, the average active power was 1.40 kW, the reactive power was 5.75 kVar, and the voltage drop was 3.28%. After optimization, these values decreased to 1.13 kW, 5.16 kVar, and 2.76%, accompanied by a significant reduction in total power loss. These findings suggest that cable size adjustment based on technical analysis is effective in improving distribution system performance and can serve as a reference for developing an efficient data-driven distribution network.