3rd most populous of 64
With 666,918 residents in 2024, Arapahoe County ranks 3rd by population among Colorado's 64 counties and is home to 11.2% of the state's residents.

Arapahoe County has the largest immigrant share in Colorado (16.5% foreign-born) and the 2nd largest economy ($66.7 billion GDP).
Arapahoe County is home to 666,918 people (2024 estimate) on 798 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 | 666,918 | 2024 · U.S. Census Bureau |
| Population, 2010 Census | 572,003 | 2010 · U.S. Census Bureau |
| Population, 2000 | 491,482 | July 1, 2000 · Census intercensal |
| Change since 2000 | +35.7% | 2000–2024 · Census |
| International migration | +8,676 | 2024 · Census Vintage 2024 |
| Domestic migration | −6,587 | 2024 · Census Vintage 2024 |
| Birth rate | 11.4 per 1,000 | 2024 · calculated |
| Death rate | 7.0 per 1,000 | 2024 · calculated |
| Population rank in Colorado | 3rd of 64 | 2024 · calculated |
| Per capita personal income | $84,131 | BEA, 2024 · official |
| Gross domestic product | $66.7 billion | BEA, current dollars, 2024 · official |
| Median household income | $101,087 | ACS 2020–2024 5-year · official |
| Poverty rate | 8.6% | ACS 2020–2024 5-year · official |
| Bachelor’s degree or higher | 46.5% | Age 25+, ACS 2020–2024 5-year · official |
| Foreign-born residents | 16.5% | ACS 2020–2024 5-year · official |
| Median home value | $561,200 | ACS 2020–2024 5-year · official |
| Median gross rent | $1,891/month | ACS 2020–2024 5-year · official |
| Median age | 37.3 years | ACS 2020–2024 5-year · official |
| Households | 257,232 | ACS 2020–2024 5-year · official |
| Owner-occupied homes | 64.7% | ACS 2020–2024 5-year · official |
Comparable indicators for Arapahoe County, Colorado and the United States.
| Indicator | County | Colorado | U.S. | Reference |
|---|---|---|---|---|
| Population change 2020–2024 | +1.8% | +3.2% | +2.6% | Census Vintage 2024 |
| Birth rate (per 1,000) | 11.4 | 10.5 | 10.6 | 2024 |
| Death rate (per 1,000) | 7.0 | 7.6 | 9.1 | 2024 |
| Net migration rate (per 1,000) | 3.1 | 6.5 | 8.2 | 2024 |
| Population density (/mi²) | 835.9 | 57.5 | 96.3 | 2024 |
| Per capita personal income | $84,131 | $83,055 | $73,204 | BEA, 2024 |
| Median household income | $101,087 | $95,470 | $80,734 | ACS 2020–2024 5-year |
| Poverty rate | 8.6% | 9.4% | 12.5% | ACS 2020–2024 5-year |
| Bachelor’s degree or higher | 46.5% | 45.7% | 35.7% | Age 25+, ACS 2020–2024 5-year |
| Foreign-born residents | 16.5% | 9.8% | 14.1% | ACS 2020–2024 5-year |
| Median home value | $561,200 | $539,400 | $332,700 | ACS 2020–2024 5-year |
| Median gross rent | $1,891/month | $1,761/month | $1,413/month | ACS 2020–2024 5-year |
| Median age | 37.3 years | 37.7 years | 38.9 years | ACS 2020–2024 5-year |
| Owner-occupied homes | 64.7% | 66.2% | 65.2% | ACS 2020–2024 5-year |
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With 666,918 residents in 2024, Arapahoe County ranks 3rd by population among Colorado's 64 counties and is home to 11.2% of the state's residents.
Its population went from 491,482 in 2000 to 666,918 in 2024, a change of +35.7%, compared with +37.7% for Colorado as a whole.
In the year to July 2024 the county recorded 7,605 births and 4,671 deaths, so births outnumbered deaths by 2,934.
Annual Census estimates since 2000 put the county's highest population in 2024, at 666,918.
Arapahoe County has about 835.9 residents per square mile of land, ranking 3rd of 64 counties; Colorado averages 57.5.
With a median household income of $101,087 (ACS 2020–2024 5-year), the county ranks 11th of 64 Colorado counties; the state median is $95,470.
Its economy produced $66.7 billion of GDP in 2024 (BEA), 2nd largest among 64 Colorado counties.
Real GDP grew 1.4% in 2024, adjusted for inflation (BEA, chained 2017 dollars).