Electric power has become a primary need for all human beings to perform daily activities. The rapidly growing population and economy each year makes the need for electricity is also increasingly increase. So the population growth as well as the people’s. economy becomes the main factor of increasing the burden of substation and transformers. Transformers is a component that has a very important role in the distribution of burdens to the community.Thus research was conducted at MRC 150kV substation in Mrica Banjarnegara which aims to know the ability of transformer in the next 20 years. At the mrica substation 150kV, there are 2 transformers that have capacity of 60 MVA each substation so can serve the needs of the citizen in Banjarnegara regency. In this research , multiple linear regression method is used to estimate transformer load during the next 20 years. The result of this research is that transformer I has heavy load in year 2024 while transformer II has heavy load in year 2034. Transformer change or addition of transformer load need to be done so that service to citizen maximize.