Portage ( /pɔrtɨdʒ/) is a city in Portage Township, Porter County, Indiana, United States. The population was 36,828 as of the 2010 census. It is the largest city in Porter County, and third largest in Northwest Indiana.
Portage is located at 41°34′55″N 87°11′12″W / 41.581850°N 87.186553°W / 41.581850; -87.186553 (41.581850, -87.186553).
According to the United States Census Bureau, the city has a total area of 27.4 square miles (71.0 km2), of which, 25.5 square miles (65.9 km2) of it is land and 2.0 square miles (5.1 km2) of it (7.18%) is water.