Porter County area

Population and density of Porter County

The Census Bureau estimates that 176,049 people lived in Porter County on July 1, 2025. That ranks #400 of 3,222 county equivalents nationally and #10 of 92 in Indiana. Since the April 1, 2020 estimates base of 173,222, the population has grown by 2,827 (+1.6%), compared with +2.8% for Indiana as a whole.

With 418.1 square miles of land, that is 421 people per square mile (163 per km²), placing Porter County #397 nationally for density and #11 in Indiana. The median county equivalent has 47 people per square mile; the Indiana median is 88. Put another way, there are about 1.5 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Porter County

11 incorporated places lie at least partly in Porter County. Together they are home to 104,166 people (59.2%); the other 71,883 (40.8%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Portage city, with 38,634 residents in the county. The county seat, Valparaiso city, has 35,177 residents. Among places with at least 1,000 residents in 2020, Burns Harbor town grew fastest since then (+4.6%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Porter County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Porter County is a central county of the Chicago-Naperville-Elgin, IL-IN Metropolitan Statistical Area, in the Lake County-Porter County-Jasper County, IN metropolitan division. Its 13 county equivalents have 9,434,123 residents on 6,923.3 square miles of land; Porter County accounts for 6% of the land and 1.9% of the residents. By combined land it ranks #27 of 393 metropolitan areas, and #3 by population. It belongs to the Chicago-Naperville, IL-IN-WI Combined Statistical Area.

ZIP codes

16 ZIP Code Tabulation Areas have land in Porter County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

46301463024630446307463414634246347463484636046368463834638546390463914639346403

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Porter County

Porter County shares a land border with 3 county equivalents. Each of them has more land than Porter County. The largest neighbor is LaPorte County (598.3 mi²) and the smallest is Lake County (498.9 mi²). Together with its neighbors, Porter County forms a block of 2,075 mi² of land, of which it holds 20.2%.

How big is Porter County compared with U.S. states?

Porter County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.5 times as much. Indiana’s county land could hold about 86 areas the size of Porter County.

Another way to picture it: the same land area would fill a square about 20.4 miles (32.9 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Porter County?

Porter County has more land than 799 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Porter County at #2,097 nationally by total area, 326 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 19.9%, compared with a national county-equivalent median of 1.2% — 18.7 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Porter County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.