Population statistics

Population estimates

Population estimates provide an up-to-date picture of how many people live in Connecticut and in its cities, towns, and counties. Unlike the decennial Census, which is conducted every 10 years, population estimates are updated annually to reflect changes such as births, deaths, and migration. Accurate population data is essential for planning and delivering health services, allocating resources, and monitoring health trends. For example, population estimates are used to calculate rates of disease and health indicators, assess community needs, examine disparities, and support emergency preparedness.

Data Available from DPH
This page provides two types of population estimate datasets prepared by the Connecticut Department of Public Health (DPH) for 2010 and onward.

  • Annual population estimates produced by the U.S. Census Bureau, reformatted to make them easier to access and use for Connecticut and its geographic areas.
  • Internally developed population estimates for Connecticut towns by age, sex, race, and ethnicity to support public health analyses at the local level.

Together, these datasets provide standardized Census-based counts and detailed demographic estimates tailored for the state’s public health needs.

Visit our archive page for population data prior to 2010.

Guidance for using population estimates



Population estimates, counts, and data sources

This interactive dashboard provides estimates of Connecticut’s population for the state, its nine planning regions (or eight historical counties), and 169 towns from 2010 to the present. It also includes data on components of population change—births, deaths, migration—and annual housing permits by town. The dashboard is the result of a collaboration between CTData and the Connecticut Department of Public Health (DPH) to provide easily accessible population estimates for data users and to help users understand changes in estimates across vintages.

Certified town population estimates provide the official annual population totals for each of Connecticut’s 169 towns. In accordance with Connecticut General Statutes § 7-51a, the Connecticut Department of Public Health prepares and certifies these estimates for official state use. Under Connecticut General Statutes § 7-51, the certified estimates may be used by state agencies and municipalities to meet statutory requirements, including funding allocations, planning, and program administration.

Annual Population Estimates Reports (PDF) (2010-present)
2010 2011  2012  2013  2014
2015 2016  2017  2018  2019
2020 2021  2022  2023  2024
2025

Annual Population Estimates Data (Excel) (2010-present)

2010 2011  2012  2013  2014
2015 2016  2017  2018  2019
2020 2021  2022  2023  2024
2025

Each year, the U.S. Census Bureau releases detailed population estimates by age, sex, race, and Hispanic origin (ASRH) for state and county-level geographies.

For 2010 and onward, race is classified using both single-race and multiple-race categories: White, Black or African American, American Indian or Alaska Native, Asian, Native Hawaiian or Other Pacific Islander, and Two or More Races. For more details, visit the Race and Ethnicity Reporting Standards page.

Summary Tables (XLSX)

State-level ASRH estimate
By 18 Age Groups: 2010-2019  2020-2024
By 19 Age Groups: 2010-2019  2020-2024

County-level ASRH estimate
By 18 Age Groups: 2010-2019  2020-2024
By 19 Age Groups:                    2020-2024

Datasets (in both csv and SAS):

Beginning in 2022, the Census Bureau recognized Connecticut’s nine planning regions as county-equivalent areas for statistical reporting and discontinued population estimates for the eight historical counties. The files below refer to these new areas as County-Equivalent Planning Regions (CEPRs). For 2020+ multi-year files, population estimates at the county-level are reported by historical county geography for 2020-2021 and by CEPR geography for 2022 and onward.

To support continued use of county-based data, the Connecticut Department of Public Health has released a parallel set of ASRH population estimates for the state's 8 counties for 2022 and later, available here: 2022-2025 County*ASRH & Methodology.

2020+ Postcensal Estimates for State and County/CEPR:
Available by single year of age for state and county/CEPR.
State_CtyCEPR_ASR6H_2020-2024
 
2010-2019 Postcensal* Estimates for State and County:
Available by single year of age for state and five-year age groups for county.
State_Cty_ASR6H_2010-2019
* Final, intercensal estimates will replace these postcensal estimates in summer 2025.

Population estimates by age, sex, race and Hispanic ethnicity (ASRH) are invaluable for the estimation of rates of health and illness in Connecticut’s towns and counties. While the Census Bureau is a primary resource for population estimates, it falls short for Connecticut in two ways: 1) the decennial estimates occur on April 1 – not the center of the calendar year, and 2) the annual town population estimates between decennial census years do not include demographics.

To address these gaps, the Connecticut Department of Public Health developed town-level ASRH data for July 1st for the following years: 2000, 2010, 2011-2014, and 2020. The town*ASRH data allows CTDPH to calculate metrics by demographic characteristics to support annual surveillance activities. These town-level estimates are also used by other state agencies to support state governance activities.

Estimates of Connecticut’s resident population as of July 1st are tabulated by 169 towns (also known as MCDs), 18 five-year age group (0-4, 5-9, 10-14 … 85 years and over), 2 sexes (male, female), and multiple race/ethnicity categories. The race/ethnicity categories vary by decade with 2020 classifying race using 7 categories (NH-White, NH-Black, NH-Am.Indian, NH-Asian, NH-NHOPI, NH-Two or More, Hispanic/Latino-any race) and 2010-2014 classifying race using 5 5 bridged-race/ethnicity categories (White, Black, Am.Indian, Asian/PI, Hispanic/Latino).

2010-2014 & 2020 Postcensal July 1 Estimates for Towns:
Town_ASRH_July 1 2010-2014 & 2020

The U.S. Census Bureau conducts a nationwide population count every 10 years, known as the decennial census. This is a major source of population data for Connecticut and aims to provide an actual count rather than an estimate. The decennial census also serves as the population base for nine years of annual estimates.

To access Census data for Connecticut geographies, visit the Connecticut State Data Center or the U.S. Census Bureau.

In addition to the decennial census, the U.S. Census Bureau publishes several other data products that provide detailed social, demographic, and economic information:

  • American Community Survey (ACS) - annually: An ongoing survey that delivers updated data each year to help communities plan investments and services. ACS data also guide the distribution of over $675 billion in federal and state funds annually.
  • Economic Census - every 5 years: Offers a comprehensive view of the U.S. economy from national to local levels. Data are used for public policy, industry analysis, disaster planning, and business development.

  • Census of Governments - every 5 years: Provides information on government organization, employment, payroll, and finances. These data support economic performance measurement, budgeting, and policy research.

  • Demographic, Economic and Other Surveys: Conducted throughout the decade to provide insights into social and economic conditions. Learn more at census.gov.

  • Economic Indicators: Includes data on manufacturing, retail and food services, housing, and international trade. View the release schedule on the Census Bureau website.

Related-data pages