Naugatuck Valley Planning Region area

Population and density of Naugatuck Valley Planning Region

The Census Bureau estimates that 463,349 people lived in Naugatuck Valley Planning Region on July 1, 2025. That ranks #161 of 3,222 county equivalents nationally and #4 of 9 in Connecticut. Since the April 1, 2020 estimates base of 450,148, the population has grown by 13,201 (+2.9%), compared with +2.2% for Connecticut as a whole.

With 412.8 square miles of land, that is 1,122 people per square mile (433 per km²), placing Naugatuck Valley Planning Region #163 nationally for density and #4 in Connecticut. The median county equivalent has 47 people per square mile; the Connecticut median is 968. Put another way, there are about 0.57 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 Naugatuck Valley Planning Region

Naugatuck Valley Planning Region is divided into 19 cities and towns. In Connecticut, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is Waterbury town, with 115,771 residents (25% of the county). The largest by land is Southbury town, at 39 mi², or 9.4% of the county’s land. Among those with at least 1,000 residents in 2020, Cheshire town grew fastest since then (+9.1%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Naugatuck Valley Planning Region. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Naugatuck Valley Planning Region is a central county of the Waterbury-Shelton, CT Metropolitan Statistical Area. Naugatuck Valley Planning Region is the area’s only county equivalent, so the metro area has the same 412.8 square miles of land. By combined land it ranks #373 of 393 metropolitan areas, and #120 by population. It belongs to the New Haven-Hartford-Waterbury, CT Combined Statistical Area.

ZIP codes

28 ZIP Code Tabulation Areas have land in Naugatuck Valley Planning Region; 26 of them have most of their land inside the county, and the others mainly cover neighboring areas.

06010060620640106403064100641806478064830648406488064920670206704067050670606708067100671206716067510676206770067790678206786067870679506798

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. Connecticut areas are assigned through their towns, because planning regions replaced the state’s counties after 2020.

Counties bordering Naugatuck Valley Planning Region

Naugatuck Valley Planning Region shares a land border with 5 county equivalents. It has more land than 2 of them. The largest neighbor is Capitol Planning Region (1,027.4 mi²) and the smallest is Greater Bridgeport Planning Region (140.2 mi²). Together with its neighbors, Naugatuck Valley Planning Region forms a block of 3,266.4 mi² of land, of which it holds 12.6%.

How big is Naugatuck Valley Planning Region compared with U.S. states?

Naugatuck Valley Planning Region 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. Connecticut’s county land could hold about 12 areas the size of Naugatuck Valley Planning Region.

Another way to picture it: the same land area would fill a square about 20.3 miles (32.7 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 Naugatuck Valley Planning Region?

Naugatuck Valley Planning Region has more land than 773 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 Naugatuck Valley Planning Region at #2,484 nationally by total area, 35 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 2.1%, compared with a national county-equivalent median of 1.2% — 0.9 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 Naugatuck Valley Planning Region 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.