2nd most populous of 99
With 231,762 residents in 2024, Linn County ranks 2nd by population among Iowa's 99 counties and is home to 7.1% of the state's residents.

Linn County has the 2nd largest economy in Iowa ($21.9 billion GDP) and the 8th highest share of college graduates (34.7% of adults).
Linn County is home to 231,762 people (2024 estimate) on 717 square miles of land. This page brings together official U.S. Census Bureau population estimates since 2000, the components of change—births, deaths and migration—American Community Survey indicators on income, housing, poverty and education, BEA economic accounts and BLS unemployment.
Pick an indicator to see its long-run evolution.
U.S. Census Bureau: intercensal estimates 2000–2009, Vintage 2020 (2010–2019) and Vintage 2024 (2020–2024), July 1.
| Indicator | Value | Year and source |
|---|---|---|
| Population estimate | 231,762 | 2024 · U.S. Census Bureau |
| Population, 2010 Census | 211,226 | 2010 · U.S. Census Bureau |
| Population, 2000 | 192,365 | July 1, 2000 · Census intercensal |
| Change since 2000 | +20.5% | 2000–2024 · Census |
| International migration | +1,686 | 2024 · Census Vintage 2024 |
| Domestic migration | +263 | 2024 · Census Vintage 2024 |
| Birth rate | 11.3 per 1,000 | 2024 · calculated |
| Death rate | 9.6 per 1,000 | 2024 · calculated |
| Population rank in Iowa | 2nd of 99 | 2024 · calculated |
| Per capita personal income | $66,525 | BEA, 2024 · official |
| Gross domestic product | $21.9 billion | BEA, current dollars, 2024 · official |
| Median household income | $77,649 | ACS 2020–2024 5-year · official |
| Poverty rate | 9.4% | ACS 2020–2024 5-year · official |
| Bachelor’s degree or higher | 34.7% | Age 25+, ACS 2020–2024 5-year · official |
| Foreign-born residents | 5.6% | ACS 2020–2024 5-year · official |
| Median home value | $214,300 | ACS 2020–2024 5-year · official |
| Median gross rent | $945/month | ACS 2020–2024 5-year · official |
| Median age | 39.0 years | ACS 2020–2024 5-year · official |
| Households | 95,600 | ACS 2020–2024 5-year · official |
| Owner-occupied homes | 73.5% | ACS 2020–2024 5-year · official |
Comparable indicators for Linn County, Iowa and the United States.
| Indicator | County | Iowa | U.S. | Reference |
|---|---|---|---|---|
| Population change 2020–2024 | +0.6% | +1.6% | +2.6% | Census Vintage 2024 |
| Birth rate (per 1,000) | 11.3 | 11.2 | 10.6 | 2024 |
| Death rate (per 1,000) | 9.6 | 10.0 | 9.1 | 2024 |
| Net migration rate (per 1,000) | 8.4 | 5.9 | 8.2 | 2024 |
| Population density (/mi²) | 323.2 | 58.0 | 96.3 | 2024 |
| Per capita personal income | $66,525 | $65,225 | $73,204 | BEA, 2024 |
| Median household income | $77,649 | $75,059 | $80,734 | ACS 2020–2024 5-year |
| Poverty rate | 9.4% | 11.1% | 12.5% | ACS 2020–2024 5-year |
| Bachelor’s degree or higher | 34.7% | 31.4% | 35.7% | Age 25+, ACS 2020–2024 5-year |
| Foreign-born residents | 5.6% | 5.9% | 14.1% | ACS 2020–2024 5-year |
| Median home value | $214,300 | $208,000 | $332,700 | ACS 2020–2024 5-year |
| Median gross rent | $945/month | $972/month | $1,413/month | ACS 2020–2024 5-year |
| Median age | 39.0 years | 38.6 years | 38.9 years | ACS 2020–2024 5-year |
| Owner-occupied homes | 73.5% | 71.7% | 65.2% | ACS 2020–2024 5-year |
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With 231,762 residents in 2024, Linn County ranks 2nd by population among Iowa's 99 counties and is home to 7.1% of the state's residents.
Its population went from 192,365 in 2000 to 231,762 in 2024, a change of +20.5%, compared with +10.7% for Iowa as a whole.
In the year to July 2024 the county recorded 2,619 births and 2,218 deaths, so births outnumbered deaths by 401.
Annual Census estimates since 2000 put the county's highest population in 2024, at 231,762.
Linn County has about 323.2 residents per square mile of land, ranking 3rd of 99 counties; Iowa averages 58.0.
With a median household income of $77,649 (ACS 2020–2024 5-year), the county ranks 20th of 99 Iowa counties; the state median is $75,059.
Its economy produced $21.9 billion of GDP in 2024 (BEA), 2nd largest among 99 Iowa counties.
Real GDP grew 1.2% in 2024, adjusted for inflation (BEA, chained 2017 dollars).