Electricity consumption by consumers is increasing in line with economic development, population growth, and development plan in the present and future. Increasing the load spent per year on the substation can affect the capacity of the transformer. This research was conducted to find out the capability of 150 kV transformer in Tegineneng until 2025. The method used is Multiple Linear Regression method and using Microsoft Excel and MATLAB software. The projection of transformer load in this study uses average load data from 2014 until 2017, population data and GDP of 2014 until 2017. The analysis shows that obtained GI Tegineneng loading rate on transformer II 30 MVA in 2022 has reached a heavy load of 29.4 MVA. The load in transformer IV 60 MVA is still optimal until 2025 which is equal to 38,8 MVA