County outline
Where Northeastern Connecticut Planning Region is located
Area breakdown
Land accounts for 98.4% of Northeastern Connecticut Planning Region’s measured area and water for 1.6%. Its combined area converts to 1,458.6 square kilometers or approximately 360,420 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 553.9 | 1,434.594 | 354,496 |
| Water | 9.256 | 23.973 | 5,923.8 |
| Total | 563.156 | 1,458.567 | 360,419.8 |
How Northeastern Connecticut Planning Region compares
By original Census land area, Northeastern Connecticut Planning Region ranks #4 of 9 in Connecticut and #1879 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.041 times the Connecticut county-equivalent median of 532.1 square miles. It accounts for 11.4% of the combined county land area in the state.
See the complete Connecticut ranking · What counts as a county equivalent?
Population and density of Northeastern Connecticut Planning Region
The Census Bureau estimates that 98,096 people lived in Northeastern Connecticut Planning Region on July 1, 2025. That ranks #643 of 3,222 county equivalents nationally and #9 of 9 in Connecticut. Since the April 1, 2020 estimates base of 95,314, the population has grown by 2,782 (+2.9%), compared with +2.2% for Connecticut as a whole.
With 553.9 square miles of land, that is 177 people per square mile (68 per km²), placing Northeastern Connecticut Planning Region #684 nationally for density and #8 in Connecticut. The median county equivalent has 47 people per square mile; the Connecticut median is 968. Put another way, there are about 3.6 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 95,212 | 95,622 | 96,121 | 96,790 | 97,627 | 98,096 |
| Change | — | +410 | +499 | +669 | +837 | +469 |
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 Northeastern Connecticut Planning Region
Northeastern Connecticut Planning Region is divided into 16 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 Killingly town, with 18,177 residents (18.5% of the county). The largest by land is Woodstock town, at 60.7 mi², or 11% of the county’s land. Among those with at least 1,000 residents in 2020, Canterbury town grew fastest since then (+4.3%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Killingly town | 18,177 | +2.6% | 48.3 | 8.7% |
| Plainfield town | 15,381 | +2.6% | 42.4 | 7.7% |
| Thompson town | 9,566 | +4.2% | 46.9 | 8.5% |
| Putnam town | 9,402 | +1.9% | 20.3 | 3.7% |
| Brooklyn town | 8,748 | +3.5% | 29.1 | 5.3% |
| Woodstock town | 8,474 | +2.9% | 60.7 | 11% |
| Canterbury town | 5,251 | +4.3% | 39.9 | 7.2% |
| Pomfret town | 4,378 | +2.6% | 40.3 | 7.3% |
| Ashford town | 4,265 | +1.8% | 38.8 | 7% |
| Sterling town | 3,736 | +4.2% | 27.2 | 4.9% |
| Voluntown town | 2,653 | +3.4% | 39 | 7% |
| Chaplin town | 2,187 | +1.8% | 19.4 | 3.5% |
| Hampton town | 1,768 | +2.1% | 25.1 | 4.5% |
| Eastford town | 1,715 | +4.3% | 28.9 | 5.2% |
| Scotland town | 1,591 | +1.7% | 18.6 | 3.4% |
Show the other 1 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Union town | 804 | +2.9% | 28.9 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Northeastern Connecticut Planning Region. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Northeastern Connecticut Planning Region is a central county of the Putnam, CT Micropolitan Statistical Area. Northeastern Connecticut Planning Region is the area’s only county equivalent, so the micro area has the same 553.9 square miles of land. By combined land it ranks #398 of 542 micropolitan areas, and #38 by population. It belongs to the New Haven-Hartford-Waterbury, CT Combined Statistical Area.
ZIP codes
32 ZIP Code Tabulation Areas have land in Northeastern Connecticut Planning Region; 26 of them have most of their land inside the county, and the others mainly cover neighboring areas.
0607606234062350623906241062420624306247062500625506256062580625906260062620626306264062770627806280062810628206330063310633206351063540637306374063770638406387
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 Northeastern Connecticut Planning Region
Northeastern Connecticut Planning Region shares a land border with 7 county equivalents, including 5 in Rhode Island and Massachusetts. It has more land than 3 of them. The largest neighbor is Worcester County (1,510.7 mi²) and the smallest is Kent County (168.6 mi²). Together with its neighbors, Northeastern Connecticut Planning Region forms a block of 5,214.4 mi² of land, of which it holds 10.6%.
| Bordering county equivalent | Land mi² | Size vs. Northeastern Connecticut | Compare |
|---|---|---|---|
| Worcester CountyMassachusetts | 1,510.7 | 2.7× larger | Compare |
| Capitol Planning Region | 1,027.4 | 1.9× larger | Compare |
| Hampden CountyMassachusetts | 617 | 1.1× larger | Compare |
| Southeastern Connecticut Planning Region | 598.1 | 1.1× larger | Compare |
| Providence CountyRhode Island | 409.5 | 1.4× smaller | Compare |
| Washington CountyRhode Island | 329.3 | 1.7× smaller | Compare |
| Kent CountyRhode Island | 168.6 | 3.3× smaller | Compare |
How big is Northeastern Connecticut Planning Region compared with U.S. states?
Northeastern Connecticut 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 1.9 times as much. Connecticut’s county land could hold about 8.7 areas the size of Northeastern Connecticut Planning Region.
Another way to picture it: the same land area would fill a square about 23.5 miles (37.9 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 Northeastern Connecticut Planning Region?
Northeastern Connecticut Planning Region has more land than 1,343 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 Northeastern Connecticut Planning Region at #1,964 nationally by total area, 85 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 1.6%, compared with a national county-equivalent median of 1.2% — 0.5 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 Northeastern Connecticut Planning Region in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1878 | Wayne County, North Carolina | 553.9 | Compare |
| #1879 | Northeastern Connecticut Planning Region, Connecticut | 553.9 | This county |
| #1880 | Cherokee County, Alabama | 553.6 | Compare |
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.
Representative coordinates
The Census internal point is 41.842375, -71.972655. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,434,595,317 m²; AWATER: 23,973,786 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Northeastern Connecticut Planning Region?
Northeastern Connecticut Planning Region, Connecticut has 553.9 square miles (1,434.6 km²) of land and 9.256 square miles of water, for a total area of 563.2 square miles. It ranks #1879 of 3,222 U.S. county equivalents by land area.
Is Northeastern Connecticut Planning Region the largest county in Connecticut?
No. Northeastern Connecticut Planning Region ranks #4 of 9 in Connecticut by land area. The largest is Capitol Planning Region, with 1,027.4 square miles of land.
What counties border Northeastern Connecticut Planning Region?
Northeastern Connecticut Planning Region shares a land border with Southeastern Connecticut Planning Region, Capitol Planning Region, Providence County, Rhode Island, Worcester County, Massachusetts, Kent County, Rhode Island, Washington County, Rhode Island, and Hampden County, Massachusetts.
What is the population of Northeastern Connecticut Planning Region?
The Census Bureau estimates Northeastern Connecticut Planning Region had 98,096 residents on July 1, 2025, ranking #643 of 3,222 county equivalents. That is 177 people per square mile of land.
What cities and towns are in Northeastern Connecticut Planning Region?
Northeastern Connecticut Planning Region has 16 county subdivisions (cities, towns and townships). The most populous five are Killingly town, Plainfield town, Thompson town, Putnam town, and Brooklyn town.
Is Northeastern Connecticut Planning Region part of a metropolitan area?
Yes. It is a central county of the Putnam, CT Micropolitan Statistical Area.
How many ZIP codes are in Northeastern Connecticut Planning Region?
32 ZIP Code Tabulation Areas have land in Northeastern Connecticut Planning Region, and 26 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Northeastern Connecticut Planning Region compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.9 times as much land.
How many acres of land are in Northeastern Connecticut Planning Region?
The land measurement converts to approximately 354,496 acres. Including water, total area is approximately 360,420 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.