U.S. Census Bureau · 2025 Population Estimates Program (PEP)
Connecticut County Population — 2025 PEP
July 1, 2025 resident population estimates for 9 counties. State total (sum of these county estimates): 3,688,496 persons.
Separate 2025 TIGER/Line county boundaries validate county identity; these are not ACS 2024 survey estimates.
Modern county equivalents are the nine planning regions, not the eight legacy counties. Original 2020 counts require separately evidenced compatible geography; incompatible observations remain null with reasons. The revised April estimates base is not an original census count; no boundary allocation is invented.
Source and downloads
2025 Census PEP county estimates, 2020–2025 series; counts are persons, migration counts are persons, published rates are per 1,000, and unavailable values remain null (not zero). 2020 rates are unavailable for the partial-year interval. County totals and characteristics are verified against the pinned raw Census CSV receipts and independent 2025 county geometry.
Official Census PEP county source · Download JSON · Download CSV · Download source metadata
Official state totals and county summaries
Official NST July 1, 2025 state total: 3,688,496 persons (SUMLEV 040, PEP Vintage 2025). County sum: 3,688,496 persons; comparison status: equal.
Official NST July 2020: 3,579,643 persons; July 2020–July 2025 change: +108,853 persons; growth: 3.040890 percent (denominator: official July 2020 population).
County July 2024–July 2025: Growing: 9 · Shrinking: 0 · Unchanged: 0 · Missing: 0. Median county growth: 0.388239 percent.
Largest county: Capitol Planning Region (GEOID 09110): 994115 persons.
Fastest county growth: Capitol Planning Region (GEOID 09110): 0.497476 percent.
Greatest numeric increase: Capitol Planning Region (GEOID 09110): 4921 persons.
no minimum population; missing excluded per measure; median of county percentages, not population weighted; equal values use ascending full GEOID.
Official state demographics
Resident population · SUMLEV 040 · July 1, 2025 · Census PEP Vintage 2025. Denominator for every share: 3,688,496 resident persons. Six exclusive race groups; Hispanic origin overlaps race and must not be added to it. Release: June 2026; exact day unproved; PEP estimates have no ACS sampling MOE.
Scroll horizontally to see Count and Share. Keyboard: focus this table region and use Left and Right arrow keys.
| Measure | Count | Share |
|---|---|---|
| Female | 1,897,669 persons | 51.448314 percent |
| Male | 1,790,827 persons | 48.551686 percent |
| Ages 18–24 | 348,096 persons | 9.437342 percent |
| Ages 25–44 | 947,572 persons | 25.689929 percent |
| Ages 45–64 | 922,688 persons | 25.015291 percent |
| Ages 65 and older | 751,845 persons | 20.383511 percent |
| Under 18 | 718,295 persons | 19.473927 percent |
| American Indian or Alaska Native alone | 47,650 persons | 1.291854 percent |
| Asian alone | 203,856 persons | 5.526806 percent |
| Black or African American alone | 500,894 persons | 13.579898 percent |
| Native Hawaiian or other Pacific Islander alone | 4,538 persons | 0.123031 percent |
| Two or more races | 158,094 persons | 4.286137 percent |
| White alone | 2,773,464 persons | 75.192273 percent |
| Hispanic (any race) | 733,559 persons | 19.887754 percent |
| Not Hispanic | 2,954,937 persons | 80.112246 percent |
Official state median age: 41.4 years. Published state SYASEX median age; not a county aggregation, not ACS.
Revised April 1, 2020 estimates base (official NST): 3,607,750 persons; county base sum: 3,607,750 persons; comparison: equal. This is not the original decennial census count.
Original April 1, 2020 Census count: 0 compatible counties; 9 unavailable. Published Census county centers-of-population POPULATION, original 2020 Gazetteer and official 2020–2025 geographic-change evidence; no boundary allocation. Original count, revised April estimates base and July 2020 estimate are separate observations. Documentation: November 2021; exact file release day unproved; retrieval is not release. Official original count source. Original 2020 Gazetteer identity plus Census geographic-change notes 2014–2025; no county-level change recorded from 2020 onward, exact full modern name, and original count required. Any recorded county-level change or referenced counterparty is conservatively unavailable, including unresolved internal redistricting. Same GEOID alone is insufficient. Not a claim of identical cartographic coordinates; no invented allocations.
Source release date unavailable: retained pins do not attest an official release date; retrieval is not release. Reference dates and Vintage 2025 are explicit; no current-vintage refresh is implied.
County population and demographic explorer
Choose a measure, observation year and county without downloading boundaries. Rankings, search, trends and CSV work without a map. Load map explicitly to download the full, unsimplified 2025 TIGER boundaries; this defers rather than removes their payload. The table remains available without JavaScript.
PEP population · persons · July 1, 2025. Denominator: none. Calculation/source: CO POPESTIMATEy. Vintage 2025; null with metric_status reason; measured zero remains zero; no imputation.
Loading county controls; static rankings available below…
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After loading, Tab to a county and press Enter or Space; colors and the legend indicate signed direction and magnitude. Outlines show selection. The county picker works before and after map loading.
Selected county demographic breakdown
July 1, 2025 · Capitol Planning Region (GEOID 09110). Same-period county population is the share denominator. Hispanic origin overlaps race; do not add origin to race counts. Other overlapping classifications are not additive. Official county median age is from PEP AGESEX MEDIAN_AGE_TOT, not ACS.
| Classification / source | Count or statistic | Share / status |
|---|---|---|
| Sex · PEP male | 481,921 persons | 48.477389 percent |
| Sex · PEP female | 512,194 persons | 51.522611 percent |
| Age bands · PEP under18 | 192,278 persons | 19.341625 percent |
| Age bands · PEP age18 24 | 101,875 persons | 10.247808 percent |
| Age bands · PEP age25 44 | 260,902 persons | 26.244650 percent |
| Age bands · PEP age45 64 | 239,151 persons | 24.056674 percent |
| Age bands · PEP age65plus | 199,909 persons | 20.109243 percent |
| Race alone (partition) · PEP white alone | 709,260 persons | 71.345870 percent |
| Race alone (partition) · PEP black alone | 159,535 persons | 16.047942 percent |
| Race alone (partition) · PEP aian alone | 9,539 persons | 0.959547 percent |
| Race alone (partition) · PEP asian alone | 71,376 persons | 7.179853 percent |
| Race alone (partition) · PEP nhpi alone | 1,144 persons | 0.115077 percent |
| Race alone (partition) · PEP two or more | 43,261 persons | 4.351710 percent |
| Hispanic origin (overlaps race) · PEP hispanic any race | 186,383 persons | 18.748636 percent |
| Hispanic origin (overlaps race) · PEP not hispanic | 807,732 persons | 81.251364 percent |
| Other overlapping classifications (not additive) · PEP white alone or combination | 748,463 persons | 75.289378 percent |
| Other overlapping classifications (not additive) · PEP not hispanic white alone | 577,539 persons | 58.095794 percent |
| Official county median age · AGESEX MEDIAN_AGE_TOT | 40.5 years | Not a share; not ACS or an average of county medians |
Use Ctrl/Command or Shift to select multiple counties. The following trend uses exact resident persons, not percentages; county size affects the scale. Missing observations break lines; the revised April estimates base is a separate dashed partial interval.
2025 county population rankings
All 9 county estimates are present without JavaScript, ranked by 2025 population (largest first). Signed changes compare July 1, 2024 to July 1, 2025. Unavailable is not zero; equal values break ties by GEOID (ascending).
Showing all 9 counties; ranked by 2025 population, descending.
| Rank | County | GEOID | Population (persons) | Signed change (persons) | Signed change (percent) |
|---|---|---|---|---|---|
| 1 | Capitol Planning Region | 09110 | 994,115 | +4921 persons | +0.497476% |
| 2 | Western Connecticut Planning Region | 09190 | 640,482 | +2761 persons | +0.432948% |
| 3 | South Central Connecticut Planning Region | 09170 | 578,741 | +1203 persons | +0.208298% |
| 4 | Naugatuck Valley Planning Region | 09140 | 463,349 | +1869 persons | +0.405001% |
| 5 | Greater Bridgeport Planning Region | 09120 | 337,697 | +1306 persons | +0.388239% |
| 6 | Southeastern Connecticut Planning Region | 09180 | 284,015 | +844 persons | +0.298053% |
| 7 | Lower Connecticut River Valley Planning Region | 09130 | 177,311 | +264 persons | +0.149113% |
| 8 | Northwest Hills Planning Region | 09160 | 114,690 | +410 persons | +0.358768% |
| 9 | Northeastern Connecticut Planning Region | 09150 | 98,096 | +469 persons | +0.480400% |
County population trend · 2020–2025
Resident population (persons), not ACS housing. April 1, 2020 estimates base is distinct from the July 1, 2020 estimate. The April–July 2020 change is partial-year; the July 2020–July 2021 interval is the first July-to-July comparison. No 2020 annual rate is shown. Missing observations are unavailable, never zero.
Showing Capitol Planning Region (GEOID 09110). Select a county on the map or in the rankings table to update this trend.
Horizontal axis: year (2020–2025); vertical axis: resident population (persons). The 2020 base is a separate April 1 observation; July 1 estimates run from 2020 through 2025. Focus the chart viewport and use Left/Right arrows to scroll on narrow screens. Complete axis labels stay here outside the scrolling chart; the table gives exact values and availability.
| Date | Population (persons) | Interval |
|---|---|---|
| April 1, 2020 base | 977,686 | Estimates base; not July 1 |
| July 1, 2020 | 964,034 | April–July partial-year; no annual rate |
| July 1, 2021 | 971,972 | July 2020–July 2021 comparison |
| July 1, 2022 | 975,074 | July-to-July estimate |
| July 1, 2023 | 981,775 | July-to-July estimate |
| July 1, 2024 | 989,194 | July-to-July estimate |
| July 1, 2025 | 994,115 | July-to-July estimate |
County population and median home value · different vintages
Each point pairs a county’s PEP July 1, 2025 resident population (persons) with its ACS 2024 5-year median owner-occupied home value (B25077, U.S. dollars). These are different reference periods and different statistical programs. This descriptive comparison does not imply causality or matched vintages. Suppressed, missing or invalid ACS estimates are unavailable, not zero and not plotted. A valid zero remains zero.
The exact-value table below works without JavaScript; chart loading requires JavaScript.
Select a county using the map or rankings to coordinate the comparison.
| County | GEOID | PEP July 1, 2025 population (persons) | ACS 2024 5-year median home value (U.S. dollars) |
|---|---|---|---|
| Capitol Planning Region | 09110 | 994,115 | $323,700 |
| Greater Bridgeport Planning Region | 09120 | 337,697 | $428,800 |
| Lower Connecticut River Valley Planning Region | 09130 | 177,311 | $379,700 |
| Naugatuck Valley Planning Region | 09140 | 463,349 | $317,700 |
| Northeastern Connecticut Planning Region | 09150 | 98,096 | $307,600 |
| Northwest Hills Planning Region | 09160 | 114,690 | $335,600 |
| South Central Connecticut Planning Region | 09170 | 578,741 | $353,100 |
| Southeastern Connecticut Planning Region | 09180 | 284,015 | $323,400 |
| Western Connecticut Planning Region | 09190 | 640,482 | $652,900 |