CT · GEOID 09180

Southeastern Connecticut Planning Region area

Southeastern Connecticut Planning Region, Connecticut covers 681.7 square miles: 598.1 square miles of land and 83.6 square miles of water.

Official Census measurements2026 Gazetteer · retrieved September 27, 2026
Land area598.1 mi²
Water area83.6 mi²
Total area681.7 mi²
National land rank#1630

County outline

Generalized outline of Southeastern Connecticut Planning Region, Connecticut
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Southeastern Connecticut Planning Region is located

Southeastern Connecticut Planning Region highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 87.7% of Southeastern Connecticut Planning Region’s measured area and water for 12.3%. Its combined area converts to 1,765.6 square kilometers or approximately 436,296 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land598.1491,549.199382,815.4
Water83.563216.42753,480.3
Total681.7121,765.626436,295.7

How Southeastern Connecticut Planning Region compares

By original Census land area, Southeastern Connecticut Planning Region ranks #3 of 9 in Connecticut and #1630 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.124 times the Connecticut county-equivalent median of 532.1 square miles. It accounts for 12.4% of the combined county land area in the state.

See the complete Connecticut ranking · What counts as a county equivalent?

What stands out about Southeastern Connecticut Planning Region?

Southeastern Connecticut Planning Region has more land than 1,592 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Southeastern Connecticut Planning Region598.1 mi²
Connecticut median532.1 mi²
National median604.5 mi²

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 Southeastern Connecticut Planning Region at #1,488 nationally by total area, 142 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 12.3%, compared with a national county-equivalent median of 1.2% — 11.1 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 Southeastern Connecticut Planning Region in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1629Hillsdale County, Michigan598.2Compare
#1630Southeastern Connecticut Planning Region, Connecticut598.1This county
#1631Darke County, Ohio598.1Compare

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 41.484769, -72.101666. 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: 1,549,197,659 m²; AWATER: 216,428,114 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How many acres of land are in Southeastern Connecticut Planning Region?

The land measurement converts to approximately 382,815 acres. Including water, total area is approximately 436,296 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.

Cite this county

Download the complete CSV or JSON dataset